JP3898616B2

JP3898616B2 - Laminated structure for high-frequency signal transmission and high-frequency semiconductor package using the same

Info

Publication number: JP3898616B2
Application number: JP2002284635A
Authority: JP
Inventors: 裕司岸田; 武宏奥道
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2002-09-30
Filing date: 2002-09-30
Publication date: 2007-03-28
Anticipated expiration: 2022-09-30
Also published as: JP2004119912A

Description

【０００１】
【発明の属する技術分野】
本発明はマイクロ波帯・ミリ波帯といった高周波において使用される積層構造および半導体素子を収容する高周波半導体パッケージに関し、特に高周波の伝送特性が良好な高周波信号伝送積層構造およびそれを用いた高周波半導体パッケージに関する。
【０００２】
【発明の背景】
上記高周波信号伝送積層構造として、本発明者は既に提案しており、（特許文献１，２を参照）、例えば、図５に示すような構造はその一例である。図５(a)は平面図、(b)は(a)のＡ−Ａ'線断面図である。また、図６及び図７に示すような構造は別の例である。図６(a)及び図７(a)は平面図、(b)は(a)のＡ−Ａ'線断面図である。
【０００３】
図５において、１は誘電体層であり、それぞれを積層することで積層板としている。11および21は信号配線導体であり、13ならびに23の信号配線接続導体を介して、14ならびに24の表層信号用貫通導体にそれぞれ接続している。内層には34の内層信号用貫通導体とそれらを接続する33の信号用貫通導体接続導体が形成され、表層信号用貫通導体14,24との間を接続しており、32の内層接地導体の内側には36に示す円形状の内層接地導体非形成領域が形成され、内層接地導体非形成領域36の外周近傍に35に示す内層接地用貫通導体が形成されている。そして、内層接地導体非形成領域36は上下に互いに重なるように配置し、表層信号用貫通導体14,24の間を内層信号用貫通導体34および信号用貫通導体接続導体33によりなめらかに接続するように順次ずらして配置することにより、高周波信号伝送用積層構造としている。
【０００４】
また、図６および図７に示す別の例では、上記図５において、前記積層基板の上面および／または下面において、表層信号用貫通導体および信号配線接続導体を取囲む状態で、信号配線導体に対し所定間隔をあけて表面接地導体を形成し、且つこの表面接地導体と内層接地導体との間を上下に貫く表層接地用貫通導体により接続している。
【０００５】
図６および図７において、図５と同様の箇所には同じ符号を付してあり、１は誘電体層であり、11および21は信号配線導体、13および23は信号配線接続導体、14および24は表層信号用貫通導体、32は内層接地導体、33は信号用貫通導体接続導体、34は内層信号用貫通導体、35は内層接地用貫通導体、36は内層接地導体非形成領域である。そして、図６は前記積層基板の上面において、表層信号用貫通導体14および信号配線接続導体13を取囲む状態で、信号配線導体に対し所定間隔をあけて12の表面接地導体を形成し、且つこの表面接地導体12と内層接地導体32との間を上下に貫く15の表層接地用貫通導体により接続している。また、図７は前記積層基板の上面および下面において、表層信号用貫通導体14,24および信号配線接続導体13,23を取囲む状態で、信号配線導体に対し所定間隔をあけて12,22の表面接地導体を形成し、且つこの表面接地導体12,22と内層接地導体32との間を上下に貫く15,25の表層接地用貫通導体により接続している。
【０００６】
しかしながら、上記高周波信号伝送用積層構造においては、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じることが考えられる。
【０００７】
本発明者は、例えば、図５の構造をなす高周波信号伝送用積層構造として、比誘電率が９．２で厚みが０．２ｍｍの誘電体層１を９層積層して積層板とし、信号配線導体１１の幅を０．２１ｍｍで形成し、信号配線接続導体１３，２３の幅を０．２１ｍｍで信号配線導体１１，２１と表面信号用貫通導体１４，２４までの距離を０．１３ｍｍにて形成し、表層信号用貫通導体１４，２４および内層信号用貫通導体３４を直径０．１ｍｍの円形状に形成し、信号用貫通導体接続導体を幅０．１６ｍｍの矩形状とし、内層接地導体非形成領域３６は直径が１．２４ｍｍの円形状に、内層接地用貫通導体３５は直径０．１ｍｍの円形状にて内層接地導体非形成領域３６の外周より中心が０．０８ｍｍだけ離れた位置の円周上の８箇所に配置することで構成し、そして、表層信号用貫通導体１４，２４および内層信号用貫通導体３４の９層間のずれを表面側から０．１９５ｍｍ，０．１１５ｍｍ，０．０７５ｍｍ，０．０５５ｍｍ，０．０５５ｍｍ，０．０７５ｍｍ，０．１１５ｍｍ，０．１９５ｍｍとした。
【０００８】
そして、表層信号配線導体11,21の信号配線接続導体13,23と反対側の端部間を上方から見て2.0mmとして、この間の高周波特性を電磁界シミュレーションにて抽出すると、図８に線図で示すような周波数特性の特性曲線が得られた。図８において、横軸は周波数（単位：ＧＨｚ）、縦軸は入力した信号のうちの反射された量の評価指標としての反射係数（単位：ｄＢ）を示しており、特性曲線は反射係数の周波数特性を示している。
【０００９】
図８における特性曲線は、45.2GHz付近に共振が生じていることを示しており、共振による使用可能周波数帯域の制限が生じていることが判明した。
【００１０】
そこで本発明は、上記高周波信号伝送用積層構造における問題点に鑑みてなされたものであり、その目的は、共振周波数を高周波側へ移動させることにより使用可能周波数の広帯域化がなされた高周波信号伝送用積層構造およびそれを用いた高周波半導体パッケージを提供することにある。
【００１１】
【特許文献１】
特願２００１−３６５１３４号
【特許文献２】
特願２００２−２０７７４号
【００１２】
【課題を解決するための手段】
本発明の請求項１に係る高周波信号伝送用積層構造は、４層以上の誘電体層を積層して成る積層基板の最上層および最下層のそれぞれに形成した信号配線導体が、互いに一端から逆方向に延びる関係にあり、これら各信号配線導体の一端と、前記最上層および前記最下層の誘電体層を上下に貫く表層信号用貫通導体とを、信号配線接続導体を介して接続し、前記最上層および前記最下層を除く内層の各層に、平面形状が円形状または楕円形状を成す内層接地導体非形成領域と、内層接地導体とを形成し、前記内層接地導体非形成領域には、前記内層の各層を上下に貫く内層信号用貫通導体に接続する信号用貫通導体接続導体を形成し、前記内層接地導体非形成領域の外周の外側に、前記内層の各層を上下に貫く内層接地用貫通導体を形成することで前記内層接地導体間を接続し、前記表層信号用貫通導体を前記内層接地導体非形成領域の外周の内側に配置し、且つ前記内層信号用貫通導体を前記表層信号用貫通導体間が接続されるように順次ずらして配置するとともに、前記内層を成す各層のうち中間に位置する層の誘電率を他の層よりも低くしたことを特徴とする。
【００１３】
これにより、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の誘電率が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００１４】
また、請求項２に係る高周波信号伝送用積層構造は、上記請求項１の構造において、前記積層基板の上面および／または下面において、前記表層信号用貫通導体および前記信号配線接続導体を取囲む状態で、前記信号配線導体に対し所定間隔をあけて表面接地導体を形成し、且つ該表面接地導体と前記内層接地導体との間を上下に貫く表層接地用貫通導体により接続したことを特徴とする。
【００１５】
これにより、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の内層接地導体非形成領域が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。さらに、入出力線路としてコプレナ線路として構成することで、外部配線がコプレナ線路の場合に、外部配線との接続におけるインピーダンスの不連続性を小さくすることができる構造となる上、共振周波数は表面接地導体および表層接地用貫通導体が設けられない場合と比較して、一方面、さらに両面に設けるにしたがって高くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００１６】
また、請求項３に係る高周波信号伝送用積層構造は、上記請求項１の構造において、前記積層基板の上面および／または下面において、前記信号配線導体に対し所定間隔をあけて表面接地導体を形成し、且つ該表面接地導体と前記内層接地導体との間を上下に貫く表層接地用貫通導体により接続したことを特徴とする。これにより、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の誘電率が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。さらに、入出力線路としてコプレナ線路として構成することで、外部配線がコプレナ線路の場合に、外部配線との接続におけるインピーダンスの不連続性を小さくすることができる構造となる上、共振周波数は表面接地導体および表層接地用貫通導体が設けられない場合と比較して、一方面、さらに両面に設けるにしたがって高くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００１７】
請求項４の高周波半導体パッケージによれば、請求項１乃至請求項３のいずれかに記載の高周波信号伝送用積層構造を備えた前記積層基板の上面に枠体および蓋体を設けることにより、高周波半導体素子を収容する構造としたことを特徴とする。ここで、本発明の高周波信号伝送用積層構造においては、特に、内層の誘電体層の厚みおよび内層接地用貫通導体の間隔を、使用する最高周波数の管内波長の半分よりも小さく設定するのが望ましい。この理由は、発明の背景で説明したように、内層に電磁遮蔽空間を形成しない場合に内層において電磁波が漏れてしまい、放射損失となってしまうことを防止するためである。すなわち、内層の上下の接地導体と接地用貫通導体がなす矩形を矩形導波管として捉えると、矩形導波管の最低次の伝送モード（基本モード）はTE10モードであり、このモードの遮断波長は矩形の長辺の２倍の実効長に等しい。したがって、使用する周波数帯域内において内層部に電磁遮蔽空間を形成するためには、内層の誘電体層の厚みおよび内層接地用貫通導体の間隔は使用する最高周波数の管内波長の半分よりも小さくすることが必要であり、より好適には４分の１波長以下に設定するのが望ましい。したがって、製造上の困難が生じない範囲で上記範囲を満たすことも重要である。
【００１８】
【発明の実施の形態】
以下、模式的に示した図面に基づいて本発明を詳細に説明する。なお、本発明は以下の例に限定されるものではなく、本発明の主旨を逸脱しない範囲で変更・改良を施すことは何ら差し支えない。
【００１９】
図１は本発明の請求項１に係る、第１の高周波信号伝送用積層構造の例を示す図であり、(a)は平面図、(b)は(a)のＡ−Ａ'線断面図である。第１の高周波信号伝送用積層構造は、４層以上の誘電体層を積層して成る積層基板の最上層と最下層を除いた内層の各誘電体層は使用する最高周波数の管内波長の半分より小さい厚みとして成し、積層基板の上面および下面に互いに逆方向に延びる信号配線導体を形成し、信号配線導体の一端は誘電体層の最上層と最下層に設けられた各層を上下に貫く表層信号用貫通導体との間をそれぞれ信号配線接続導体を介して接続し、積層基板の上面および下面に表層信号用貫通導体を形成し、内層の各層には内層接地導体を円形状や楕円形状等の２軸対称形状に設けた内層接地導体非形成領域を除いて略全面に形成し、これらの内層接地導体非形成領域は互いに上下に重なり合うように配置し、内層接地導体非形成領域の内側には誘電体層の内層の各層を上下に貫く内層信号用貫通導体のそれぞれを接続する信号用貫通導体接続導体を形成するとともに、使用する最高周波数の管内波長の半分よりも短い間隔をあけて内層接地導体非形成領域の外周近傍に内層の各層を上下に貫く複数の内層接地用貫通導体を配設することにより内層部に電磁遮蔽空間を形成し、表層信号用貫通導体と内層信号用貫通導体との間を信号用貫通導体接続導体を介して接続することにより積層基板の上下面の間を電気的に接続し、表層信号用貫通導体は信号配線接続導体の長さが短くなるように内層接地導体非形成領域の外周近傍に配置するとともに、内層信号用貫通導体を表層信号用貫通導体間をなめらかに接続するように順次ずらして配置した高周波信号伝送用積層構造において、内層を成す各層のうち中間に位置する層の誘電率を、他の層の誘電率よりも小さくなるように形成した。
【００２０】
すなわち、図１において、１は誘電体層でありそれぞれを積層することで積層板としている。11および21は信号配線導体であり13ならびに23の信号配線接続導体を介して14ならびに24の表層信号用貫通導体にそれぞれ接続している。内層には34の内層信号用貫通導体とそれらを接続する33の信号用貫通導体接続導体が形成され、表層信号用貫通導体14,24との間を接続しており、32の内層接地導体の内側には36に示す円形状の内層接地導体非形成領域が形成され、内層接地導体非形成領域36の外周近傍に35に示す内層接地用貫通導体が形成されている。そして、内層接地導体非形成領域36は上下に互いに重なるように配置し、表層信号用貫通導体14,24の間を内層信号用貫通導体34および信号用貫通導体接続導体33によりなめらかに接続するように順次ずらして配置し、内層を成す各層のうち37に示す中間層近傍の内層の誘電率εr1を他層の誘電率εr2よりも小さい層として形成した。
【００２１】
これにより、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の内層接地導体非形成領域が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００２２】
次に、図２および図３は本発明の請求項２に係る、第２の高周波信号伝送用積層構造の例を示す図であり、各図において、(a)は平面図、(b)は(a)のＡ−Ａ'線断面図である。第２の高周波信号伝送用積層構造は、上記第１の高周波信号伝送用積層構造において、前記積層基板の上面および／または下面において、表層信号用貫通導体および信号配線接続導体を取囲む状態で、信号配線導体に対し所定間隔をあけて表面接地導体を形成し、且つこの表面接地導体と内層接地導体との間を上下に貫く表層接地用貫通導体により接続した。
【００２３】
図２および図３において、図１と同様の箇所には同じ符号を付してあり、１は誘電体層であり、11および21は信号配線導体、13および23は信号配線接続導体、14および24は表層信号用貫通導体、32は内層接地導体、33は信号用貫通導体接続導体、34は内層信号用貫通導体、35は内層接地用貫通導体、36は内層接地導体非形成領域、37は共振制御層である。そして、図２は前記積層基板の上面において、表層信号用貫通導体14および信号配線接続導体13を取囲む状態で、信号配線導体に対し所定間隔をあけて12の表面接地導体を形成し、且つこの表面接地導体12と内層接地導体32との間を上下に貫く15の表層接地用貫通導体により接続している。また、図３は前記積層基板の上面および下面において、表層信号用貫通導体14,24および信号配線接続導体13,23を取囲む状態で、信号配線導体に対し所定間隔をあけて12,22の表面接地導体を形成し、且つこの表面接地導体12,22と内層接地導体32との間を上下に貫く15,25の表層接地用貫通導体により接続している。
【００２４】
これにより、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の誘電率が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。さらに、入出力線路としてコプレナ線路として構成することで、外部配線がコプレナ線路の場合に、外部配線との接続におけるインピーダンスの不連続性を小さくすることができる構造となる上、共振周波数は表面接地導体および表層接地用貫通導体が設けられない場合と比較して、一方面（図２に相当）、さらに両面（図３に相当）に設けるにしたがって高くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００２５】
次に、図９は本発明の請求項３に係る、第２の高周波信号伝送用積層構造の他の例を示す図であり、各図において、(a)は平面図、(b)は(a)のＡ−Ａ'線断面図である。第２の高周波信号伝送用積層構造の他の例は、上記第１の高周波信号伝送用積層構造において、前記積層基板の上面および／または下面において、信号配線導体に対し所定間隔をあけて表面接地導体を形成し、且つこの表面接地導体と内層接地導体との間を上下に貫く表層接地用貫通導体により接続した。
【００２６】
図９において、図１と同様の箇所には同じ符号を付してあり、１は誘電体層であり、11および21は信号配線導体、13および23は信号配線接続導体、14および24は表層信号用貫通導体、32は内層接地導体、33は信号用貫通導体接続導体、34は内層信号用貫通導体、35は内層接地用貫通導体、36は内層接地導体非形成領域、37は共振制御層である。そして、前記積層基板の上面において、信号配線導体11に対し所定間隔をあけて12の表面接地導体を形成し、且つこの表面接地導体12と内層接地導体32との間を上下に貫く15の表層接地用貫通導体により接続している。
【００２７】
これにより、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の誘電率が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。さらに、入出力線路としてコプレナ線路として構成することで、外部配線がコプレナ線路の場合に、外部配線との接続におけるインピーダンスの不連続性を小さくすることができる構造となる上、共振周波数は表面接地導体および表層接地用貫通導体が設けられない場合と比較して、一方面（図９に相当）、さらに両面に設けるにしたがって高くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００２８】
また、上記高周波信号伝送用積層構造を高周波半導体パッケージに適用が可能である。すなわち、上記積層基板の上面に高周波半導体素子を収容するように枠体および蓋体を形成し、積層基板の下面の信号配線導体に外部との信号入出力のための入出力信号配線接続導体を形成することにより、高周波の伝送特性が良好な高周波半導体パッケージとなる。
【００２９】
このような本発明の高周波半導体パッケージにおいて、誘電体基板としては、例えばアルミナやムライト、窒化アルミ等のセラミックス材料、いわゆるガラセラ（ガラス＋セラミック）材料が広く用いられ、信号配線導体や接地導体といった導体パターンは、高周波配線導体用の金属材料、例えば、Ｃｕなどの単体金属やＭｏＭｎ＋Ｎｉ＋Ａｕ、Ｗ＋Ｎｉ＋Ａｕ、Ｃｒ＋Ｃｕ、Ｃｒ＋Ｃｕ＋Ｎｉ＋Ａｕ、Ｔａ _２Ｎ＋ＮｉＣｒ＋Ａｕ、Ｔｉ＋Ｐｄ＋Ａｕ、ＮｉＣｒ＋Ｐｄ＋Ａｕなどの合金を用いて厚膜印刷法あるいは各種の薄膜形成方法やメッキ処理法などにより形成される。また、その厚みや幅も伝送される高周波信号の周波数や使用する特性インピーダンスなどに応じて誘電体の誘電率や厚みとともに設定される。また、枠体や蓋体に金属を用いる場合には、Ｆｅ−Ｎｉ−ＣｏやＦｅ−Ｎｉ４２アロイ等のＦｅ−Ｎｉ合金・無酸素銅・アルミニウム・ステンレス・Ｃｕ−Ｗ合金・Ｃｕ−Ｍｏ合金などから成る材料を用い、金属構造物間の接合には、ハンダ・ＡｕＳｎロウやＡｕＧｅロウ等の高融点金属ロウ・シームウェルド（溶接）等により取着することによって気密封止し、また、誘電体基板と金属構造物とは、ＡｇＣｕロウ・ＡｕＳｎロウ・ＡｕＧｅロウ等の高融点金属ロウにより接合することによって、半導体素子を収容することで良好な伝送特性を有する高周波半導体パッケージを提供できる。
【００３０】
【実施例】
次に、本発明の高周波信号伝送用積層構造について具体例を説明する。
【００３１】
まず、本発明の請求項３に係る高周波信号伝送用積層構造を示す図３と同様の構成にて、誘電体層1は比誘電率が10、ただし、共振制御層37の比誘電率が8.5、厚みが0.2mmで９層積層して積層板とし、上面および下面の信号配線導体11,21の線幅を0.14mmとし、内層の信号配線導体11の幅を0.21mmとし、上面および下面の信号配線接続導体13,23の線幅を0.16mmとし、内層の信号配線接続導体13,23の幅を0.21mmとし、信号配線導体11,21と表面信号用貫通導体14,24までの距離を0.13mmとし、表層信号用貫通導体14,24および内層信号用貫通導体34を直径0.1mmの円形状とし、信号用貫通導体接続導体を幅0.16mmの矩形状とし、内層接地内層接地導体非形成領域36は直径が1.24mmの円形状とし、内層接地用貫通導体35は直径0.1mmの円形状にて内層接地導体非形成領域36の外周より中心が0.08mmだけ離れた位置の円周上の８箇所に配置することで構成し、上面および下面には表層信号用貫通導体14,24および信号配線接続導体13,23を取囲む状態で内層接地導体非形成領域36と形状を一致させて、信号配線導体11,21に対し0.10mmの間隔をあけて表面接地導体12,22を形成し、さらにこの表面接地導体12,22と内層接地導体32との間を上下に貫く直径0.1mmの表層接地用貫通導体15,25により接続そして、表層信号用貫通導体14,24および内層信号用貫通導体34の９層間のずれを表面側から0.195mm, 0.115mm, 0.075mm, 0.055mm, 0.055mm, 0.075mm, 0.115mm, 0.195mmとし、表層信号配線導体11,21の信号配線接続導体13,23と反対側の端部間を上方から見て2.0mmとし、共振制御層37の比誘電率を8.5とすることにより、本発明の高周波信号伝送用積層構造の試料Ａを得た。また、前記試料Ａと同様に、ただし、共振制御層37の比誘電率を6とすることにより、本発明の高周波信号伝送用積層構造の試料Ｂを得た。
【００３２】
さらに、比較例としての高周波信号伝送用積層構造を示す図７と同様の構成にて、上記試料Ａに対して共振制御層を設けず、共振制御層37の比誘電率を全ての層で同一である10とすることにより、比較例としての高周波信号伝送用積層構造の試料Ｃを得た。
【００３３】
そして、これらの試料Ａ・Ｂ・Ｃについて下面の信号配線導体21の端部から上面の信号配線導体11の端部間の電気的特性を電磁界シミュレーションにより抽出すると、図４に線図で示すような周波数特性の特性曲線が得られた。図４において、横軸は周波数（単位：ＧＨｚ）、縦軸は入力した信号のうちの反射された量の評価指標としての反射係数（単位：ｄＢ）を示しており、特性曲線は反射係数の周波数特性を示している。また、特性曲線に付記したＡ・Ｂ・Ｃは各々試料Ａ・Ｂ・Ｃの特性曲線であることを示している。
【００３４】
この結果から、本発明の高周波信号伝送用積層構造である試料Ｂは共振周波数が54.8GHzであり、また、本発明の高周波信号伝送用積層構造である試料Ａは共振周波数が56.0GHzであり、比較例としての高周波信号伝送用積層構造である試料Ｃの共振周波数が53.8GHzであるのに対して、共振周波数が高周波側に移動しており、広帯域化がなされた高周波信号伝送用積層構造であることが分かる。特に、共振制御層37の誘電率が最も小さい試料Ａにおいて、その傾向は顕著であり、より広帯域化がなされた。
【００３５】
なお、以上はあくまで本発明の実施形態の例示であって、本発明はこれらに限定されるものではなく、本発明の要旨を逸脱しない範囲で種々の変更や改良を加えることは何ら差し支えない。
【００３６】
例えば、本発明の実施形態の例示では、共振制御層を１層とし、他の層と同一の厚さとしたが、複数層としてもよく、また共振制御層の厚さを、他の層の厚さと異なる厚さとしても同様の効果が得られる。ただし、共振制御層として設けられる層が増加すれば伝送距離が増加するためにリアクタンス減衰量は増加するので、遮断効果が期待できるが、その距離が長くなり過ぎると、遮断周波数までの周波数においては容量が増加するために特性インピーダンスの低下が顕著に現れるために、反射の増大を招くという悪影響があるので、その距離すなわち共振制御層として設けられる層の厚さは適宜決定すれば良い。
【００３７】
【発明の効果】
以上のように、請求項１の高周波信号伝送用積層構造によれば、４層以上の誘電体層を積層して成る積層基板の最上層および最下層のそれぞれに形成した信号配線導体が、互いに一端から逆方向に延びる関係にあり、これら各信号配線導体の一端と、前記最上層および前記最下層の誘電体層を上下に貫く表層信号用貫通導体とを、信号配線接続導体を介して接続し、前記最上層および前記最下層を除く内層の各層に、平面形状が円形状または楕円形状を成す内層接地導体非形成領域と、内層接地導体とを形成し、前記内層接地導体非形成領域には、前記内層の各層を上下に貫く内層信号用貫通導体に接続する信号用貫通導体接続導体を形成し、前記内層接地導体非形成領域の外周の外側に、前記内層の各層を上下に貫く内層接地用貫通導体を形成することで前記内層接地導体間を接続し、前記表層信号用貫通導体を前記信号配線接続導体の長さが短くなるように、前記内層接地導体非形成領域の外周の内側に配置し、前記内層信号用貫通導体を前記表層信号用貫通導体間がなめらかに接続されるように順次ずらして配置するとともに、前記内層を成す各層のうち中間に位置する層の誘電率を、他の層よりも小さくしたことから、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の誘電率が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（ＴＥ１１モード）の遮断周波数が他層の円筒導波管モード（ＴＥ１１モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００３８】
また、請求項２の高周波信号伝送用積層構造によれば、請求項１の高周波信号伝送用積層構造において、前記積層基板の上面および／または下面において、前記表層信号用貫通導体および前記信号配線接続導体を取囲む状態で、前記信号配線導体に対し所定間隔をあけて表面接地導体を形成し、且つ該表面接地導体と前記内層接地導体との間を上下に貫く表層接地用貫通導体により接続したことから、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の誘電率が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。さらに、入出力線路としてコプレナ線路として構成することで、外部配線がコプレナ線路の場合に、外部配線との接続におけるインピーダンスの不連続性を小さくすることができる構造となる上、共振周波数は表面接地導体および表層接地用貫通導体が設けられない場合と比較して、一方面、さらに両面に設けるにしたがって高くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００３９】
また、請求項３の高周波信号伝送用積層構造によれば、請求項１の高周波信号伝送用積層構造において、前記積層基板の上面および／または下面において、前記信号配線導体に対し所定間隔をあけて表面接地導体を形成し、且つ該表面接地導体と前記内層接地導体との間を上下に貫く表層接地用貫通導体により接続したことから、内層部において内層接地導体および内層接地用貫通導体で取り囲まれた電磁遮蔽空間が形成されているために、この電磁遮蔽空間が円筒誘電体共振器として働く結果、共振による使用可能周波数帯域の制限が生じる場合と比較して、中間層近傍の誘電率が小さくなっていることで共振制御層として働き、すなわち、共振制御層における円筒導波管モード（TE11モード）の遮断周波数が他層の円筒導波管モード（TE11モード）の遮断周波数よりも高いためにリアクタンス減衰器とみなされることから高次モード伝搬が抑圧される結果、円筒誘電体共振モードに準じた共振は高周波側へ移動するために、使用可能周波数帯域が広くなる。さらに、入出力線路としてコプレナ線路として構成することで、外部配線がコプレナ線路の場合に、外部配線との接続におけるインピーダンスの不連続性を小さくすることができる構造となる上、共振周波数は表面接地導体および表層接地用貫通導体が設けられない場合と比較して、一方面（図９に相当）、さらに両面に設けるにしたがって高くなる。その結果、使用可能周波数帯域の広帯域化がなされた高周波信号伝送用積層構造となる。
【００４０】
さらに、請求項４の高周波半導体パッケージによれば、例えば請求項１乃至２の高周波信号伝送用積層構造を有する積層基板の上面に高周波半導体素子を収容するように枠体および蓋体を形成し、積層基板の下面の信号配線導体に外部との信号入出力のための入出力信号配線接続導体を形成したことにより、高周波の伝送特性が良好な高周波半導体パッケージとして提供できる。
【図面の簡単な説明】
【図１】本発明に係る第１の高周波信号伝送用積層構造の一例を模式的に示す図であり、(a)は平面図、(b)は(a)のA-A'線断面図である。
【図２】本発明に係る第２の高周波信号伝送用積層構造の一例を模式的に示す図であり、(a)は平面図、(b)は(a)のA-A'線断面図である。
【図３】本発明に係る第２の高周波信号伝送用積層構造の一例を模式的に示す図であり、(a)は平面図、(b)は(a)のA-A'線断面図である。
【図４】本発明の第２の高周波信号伝送用積層構造および比較例としての高周波信号伝送用積層構造の高周波特性を比較した線図である。
【図５】高周波信号伝送用積層構造の一比較例を示す平面図ならびに断面図である。
【図６】高周波信号伝送用積層構造の他の比較例を示す平面図ならびに断面図である。
【図７】高周波信号伝送用積層構造のさらに他の比較例を示す平面図ならびに断面図である。
【図８】高周波信号伝送用積層構造（比較例）の高周波特性例を示す線図である。
【図９】本発明に係る第２の高周波信号伝送用積層構造の他の一例を模式的に示す図であり、(a)は平面図、(b)は(a)のA-A'線断面図である。
【符号の説明】
１・・・・・誘電体層
11,21・・・・・信号配線導体
12,22・・・・・表面接地導体
13,23・・・・・信号配線接続導体
14,24・・・・・表層信号用貫通導体
15,25・・・・・表層接地用貫通導体
16,26・・・・・表面接地導体非形成領域
32・・・・・内層接地導体
33・・・・・信号用貫通導体接続導体
34・・・・・内層信号用貫通導体
35・・・・・内層接地用貫通導体
36・・・・・内層接地導体非形成領域
37・・・・・共振制御層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated structure used at high frequencies such as a microwave band and a millimeter wave band, and a high-frequency semiconductor package containing a semiconductor element, and particularly to a high-frequency signal transmission laminated structure having good high-frequency transmission characteristics and a high-frequency semiconductor package using the same. About.
[0002]
BACKGROUND OF THE INVENTION
The present inventor has already proposed the high-frequency signal transmission laminated structure (see Patent Documents 1 and 2). For example, the structure shown in FIG. 5 is an example. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along the line AA ′ in FIG. Further, the structure as shown in FIGS. 6 and 7 is another example. FIGS. 6A and 7A are plan views, and FIG. 6B is a cross-sectional view taken along the line AA ′ in FIG.
[0003]
In FIG. 5, reference numeral 1 denotes a dielectric layer which is laminated to form a laminated plate. The signal wiring conductors 11 and 21 are connected to the surface signal through conductors 14 and 24 through the signal wiring connecting conductors 13 and 23, respectively. In the inner layer, 34 inner layer signal through conductors and 33 signal through conductor connecting conductors connecting them are formed and connected between the surface layer signal through conductors 14, 24, and 32 inner layer ground conductors are connected. A circular inner layer ground conductor non-formation region indicated by 36 is formed inside, and an inner layer grounding through conductor indicated by 35 is formed in the vicinity of the outer periphery of the inner layer ground conductor non-formation region. The inner-layer ground conductor non-formation regions 36 are arranged so as to overlap each other vertically so that the inner-layer signal through conductors 14 and 24 are smoothly connected by the inner-layer signal through conductors 34 and the signal through conductor connecting conductors 33. In this way, a stacked structure for high-frequency signal transmission is obtained.
[0004]
Further, in another example shown in FIG. 6 and FIG. 7, in FIG. 5, the signal wiring conductor in the state surrounding the surface signal through conductor and the signal wiring connecting conductor on the upper surface and / or the lower surface of the multilayer substrate. The surface ground conductor is formed at a predetermined interval, and the surface ground conductor and the inner layer ground conductor are connected by a surface layer ground through conductor that passes vertically.
[0005]
6 and 7, the same parts as those in FIG. 5 are denoted by the same reference numerals, 1 is a dielectric layer, 11 and 21 are signal wiring conductors, 13 and 23 are signal wiring connecting conductors, 14 and Reference numeral 24 is a surface layer signal through conductor, 32 is an inner layer ground conductor, 33 is a signal through conductor connecting conductor, 34 is an inner layer signal through conductor, 35 is an inner layer ground through conductor, and 36 is an inner layer ground conductor non-forming region. FIG. 6 is a plan view of the top surface of the multilayer substrate, in which 12 surface ground conductors are formed at predetermined intervals with respect to the signal wiring conductor in a state of surrounding the surface signal through conductors 14 and the signal wiring connecting conductors 13; The surface ground conductor 12 and the inner layer ground conductor 32 are connected by 15 surface layer ground through conductors that penetrate vertically. Further, FIG. 7 shows a state in which the surface layer signal through conductors 14 and 24 and the signal wiring connecting conductors 13 and 23 are surrounded on the upper and lower surfaces of the multilayer substrate with a predetermined distance from the signal wiring conductors 12 and 22. A surface ground conductor is formed, and the surface ground conductors 12 and 22 and the inner layer ground conductor 32 are connected by 15 and 25 surface layer ground through conductors passing vertically.
[0006]
However, in the laminated structure for high-frequency signal transmission, since the electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion, this electromagnetic shielding space serves as a cylindrical dielectric resonator. As a result, it is considered that the usable frequency band is restricted due to resonance.
[0007]
  The inventor, for example, as a laminated structure for high-frequency signal transmission having the structure shown in FIG. 5, nine dielectric layers 1 having a relative dielectric constant of 9.2 and a thickness of 0.2 mm are laminated to form a laminated plate. The width of the wiring conductor 11 is 0.21 mm, the width of the signal wiring connecting conductors 13 and 23 is 0.21 mm, and the distance between the signal wiring conductors 11 and 21 and the surface signal through conductors 14 and 24 is 0.13 mm. The surface signal through conductors 14 and 24 and the inner layer signal through conductor 34 are formed in a circular shape with a diameter of 0.1 mm, and the signal through conductor connecting conductor is formed into a rectangular shape with a width of 0.16 mm.InsideThe layer ground conductor non-forming region 36 has a circular shape with a diameter of 1.24 mm, the inner layer grounding through conductor 35 has a circular shape with a diameter of 0.1 mm, and the center is 0.08 mm from the outer periphery of the inner layer ground conductor non-forming region 36. It is configured by disposing at 8 locations on the circumference at a distance, and the deviation between the nine layers of the surface signal through conductors 14 and 24 and the inner layer signal through conductor 34 is 0.195 mm, 0. 115 mm, 0.075 mm, 0.055 mm, 0.055 mm, 0.075 mm, 0.115 mm, and 0.195 mm.
[0008]
Then, when the distance between the ends of the surface signal wiring conductors 11 and 21 opposite to the signal wiring connecting conductors 13 and 23 is 2.0 mm when viewed from above, and the high frequency characteristics between them are extracted by electromagnetic field simulation, the line in FIG. A characteristic curve of frequency characteristics as shown in the figure was obtained. In FIG. 8, the horizontal axis indicates the frequency (unit: GHz), the vertical axis indicates the reflection coefficient (unit: dB) as an evaluation index of the reflected amount of the input signal, and the characteristic curve indicates the reflection coefficient. The frequency characteristics are shown.
[0009]
The characteristic curve in FIG. 8 shows that resonance occurs in the vicinity of 45.2 GHz, and it has been found that the usable frequency band is limited by resonance.
[0010]
Therefore, the present invention has been made in view of the problems in the above-described laminated structure for high-frequency signal transmission, and the object thereof is high-frequency signal transmission in which the usable frequency is widened by moving the resonance frequency to the high-frequency side. An object of the present invention is to provide a laminated structure for use and a high-frequency semiconductor package using the same.
[0011]
[Patent Document 1]
Japanese Patent Application No. 2001-365134
[Patent Document 2]
Japanese Patent Application No. 2002-20774
[0012]
[Means for Solving the Problems]
  In the laminated structure for high-frequency signal transmission according to claim 1 of the present invention, the signal wiring conductors formed on the uppermost layer and the lowermost layer of the laminated substrate formed by laminating four or more dielectric layers are reversed from one end. The signal wiring conductor is connected to one end of each of the signal wiring conductors, and the surface layer signal through conductors vertically passing through the uppermost layer and the lowermost dielectric layer via the signal wiring connection conductors, Each layer of the inner layer excluding the uppermost layer and the lowermost layer has a planar shape.Circular or elliptical shapeAn inner-layer ground conductor non-forming region and an inner-layer ground conductor are formed, and in the inner-layer ground conductor non-forming region, a signal through-conductor connecting conductor is connected to an inner-layer signal through-conductor that vertically penetrates each layer of the inner layer. Forming an outer periphery of the inner-layer ground conductor non-forming regionOutsideThe inner layer grounding conductors are formed by penetrating the inner layers through the inner layer, and the inner layer grounding conductors are connected to each other, and the surface layer signal through conductors are connected to the outer periphery of the inner layer grounding conductor non-forming region.InsideAnd the inner layer signal through conductors are sequentially shifted so that the surface layer signal through conductors are connected to each other, and the dielectric constant of the middle layer among the layers constituting the inner layer is changed to another It is characterized by being lower than the layer.
[0013]
As a result, an electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion. As a result of this electromagnetic shielding space acting as a cylindrical dielectric resonator, the usable frequency band due to resonance Compared with the case where the restriction occurs, it works as a resonance control layer because the dielectric constant near the intermediate layer is small, that is, the cutoff frequency of the cylindrical waveguide mode (TE11 mode) in the resonance control layer is the other layer Because it is considered as a reactance attenuator because it is higher than the cut-off frequency of the cylindrical waveguide mode (TE11 mode), higher-order mode propagation is suppressed. As a result, resonance according to the cylindrical dielectric resonance mode moves to the high-frequency side. Therefore, the usable frequency band is widened. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0014]
The multilayer structure for high-frequency signal transmission according to claim 2 is a state in which the surface signal through conductor and the signal wiring connecting conductor are surrounded on the upper surface and / or the lower surface of the multilayer substrate in the structure according to claim 1. The surface ground conductor is formed at a predetermined interval with respect to the signal wiring conductor, and the surface ground conductor and the inner layer ground conductor are connected by a surface layer ground penetrating conductor that extends vertically. .
[0015]
As a result, an electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion. As a result of this electromagnetic shielding space acting as a cylindrical dielectric resonator, the usable frequency band due to resonance Compared with the case where there is a restriction, the region where the inner ground conductor is not formed near the intermediate layer is reduced, so that it functions as a resonance control layer, that is, the cylindrical waveguide mode (TE11 mode) is cut off in the resonance control layer. As the frequency is higher than the cutoff frequency of the cylindrical waveguide mode (TE11 mode) of other layers, it is regarded as a reactance attenuator. As a result, high-order mode propagation is suppressed, and resonance according to the cylindrical dielectric resonance mode is In order to move to the high frequency side, the usable frequency band is widened. In addition, by configuring as a coplanar line as an input / output line, when the external wiring is a coplanar line, the impedance discontinuity in connection with the external wiring can be reduced, and the resonance frequency is surface grounded. Compared to the case where the conductor and the surface layer grounding through conductor are not provided, the height becomes higher as the conductor is provided on one side and further on both sides. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0016]
According to a third aspect of the present invention, there is provided a multilayer structure for high-frequency signal transmission in which the surface ground conductor is formed on the upper surface and / or the lower surface of the multilayer substrate at a predetermined interval from the signal wiring conductor. In addition, the surface ground conductor and the inner layer ground conductor are connected by a surface layer ground through conductor that passes vertically. As a result, an electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion. As a result of this electromagnetic shielding space acting as a cylindrical dielectric resonator, the usable frequency band due to resonance Compared with the case where the restriction occurs, it works as a resonance control layer because the dielectric constant near the intermediate layer is small, that is, the cutoff frequency of the cylindrical waveguide mode (TE11 mode) in the resonance control layer is the other layer Because it is considered as a reactance attenuator because it is higher than the cut-off frequency of the cylindrical waveguide mode (TE11 mode), higher-order mode propagation is suppressed. As a result, resonance according to the cylindrical dielectric resonance mode moves to the high-frequency side. Therefore, the usable frequency band is widened. In addition, by configuring as a coplanar line as an input / output line, when the external wiring is a coplanar line, the impedance discontinuity in connection with the external wiring can be reduced, and the resonance frequency is surface grounded. Compared to the case where the conductor and the surface layer grounding through conductor are not provided, the height becomes higher as the conductor is provided on one side and further on both sides. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0017]
According to a high frequency semiconductor package of a fourth aspect, a frame and a lid are provided on the upper surface of the multilayer substrate provided with the multilayer structure for high frequency signal transmission according to any one of the first to third aspects. The structure is characterized in that it contains a semiconductor element. Here, in the laminated structure for high-frequency signal transmission of the present invention, in particular, the thickness of the inner dielectric layer and the interval between the inner-layer grounding through conductors are set to be smaller than half of the maximum guide wavelength used. desirable. This is because, as described in the background of the invention, when an electromagnetic shielding space is not formed in the inner layer, electromagnetic waves leak in the inner layer and prevent radiation loss. In other words, if the rectangle formed by the upper and lower ground conductors on the inner layer and the grounding through conductor is regarded as a rectangular waveguide, the lowest transmission mode (basic mode) of the rectangular waveguide is the TE10 mode. Is equal to the effective length of twice the long side of the rectangle. Therefore, in order to form an electromagnetic shielding space in the inner layer portion within the frequency band to be used, the thickness of the inner dielectric layer and the interval between the inner layer grounding through conductors should be smaller than half of the highest frequency of the guide wavelength used. It is necessary to set it to 1/4 wavelength or less. Therefore, it is also important to satisfy the above range within a range where manufacturing difficulties do not occur.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings schematically shown. In addition, this invention is not limited to the following examples, It does not interfere at all in the range which does not deviate from the main point of this invention.
[0019]
1A and 1B are diagrams showing an example of a first laminated structure for high-frequency signal transmission according to claim 1 of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA ′ in FIG. FIG. In the first laminated structure for high frequency signal transmission, each dielectric layer of the inner layer excluding the uppermost layer and the lowermost layer of the laminated substrate formed by laminating four or more dielectric layers is half of the highest frequency of the guide wavelength used. The signal wiring conductor is formed with a smaller thickness and extends in opposite directions on the upper and lower surfaces of the multilayer substrate, and one end of the signal wiring conductor penetrates the layers provided on the uppermost layer and the lowermost layer of the dielectric layer up and down. Connected to the surface signal through conductors via signal wiring connection conductors, surface signal through conductors are formed on the upper and lower surfaces of the multilayer substrate, and inner layer ground conductors are circular or oval on each inner layer The inner layer ground conductor non-formation area provided in a biaxial symmetry shape is formed on substantially the entire surface, and these inner layer ground conductor non-formation areas are arranged so as to overlap each other, inside the inner layer ground conductor non-formation area Of the inner layer of the dielectric layer Form the signal through conductor connecting conductor that connects each of the inner layer signal through conductors that penetrate the layers up and down, and at the outer periphery of the inner layer ground conductor non-formation area with an interval shorter than half of the highest frequency in the tube to be used An electromagnetic shielding space is formed in the inner layer by arranging a plurality of inner-layer grounding through conductors that vertically penetrate each layer of the inner layer in the vicinity, and signal penetration is made between the surface layer signal through conductor and the inner layer signal through conductor. Electrical connection is made between the upper and lower surfaces of the multilayer substrate by connecting via conductor connection conductors, and the outer periphery of the inner-layer ground conductor non-formation region is such that the length of the signal wiring connection conductor is shortened for the surface layer signal through conductors In the laminated structure for high-frequency signal transmission in which the inner layer signal through conductors are arranged in the vicinity and sequentially shifted so as to smoothly connect the surface layer signal through conductors, The dielectric constant of the layer positioned and formed to be smaller than the dielectric constant of the other layers.
[0020]
That is, in FIG. 1, reference numeral 1 denotes a dielectric layer which is laminated to form a laminated plate. The signal wiring conductors 11 and 21 are connected to the surface signal through conductors 14 and 24 through the signal wiring connecting conductors 13 and 23, respectively. In the inner layer, 34 inner layer signal through conductors and 33 signal through conductor connecting conductors connecting them are formed and connected between the surface layer signal through conductors 14, 24, and 32 inner layer ground conductors are connected. A circular inner layer ground conductor non-formation region indicated by 36 is formed inside, and an inner layer grounding through conductor indicated by 35 is formed in the vicinity of the outer periphery of the inner layer ground conductor non-formation region. The inner-layer ground conductor non-formation regions 36 are arranged so as to overlap each other vertically so that the inner-layer signal through conductors 14 and 24 are smoothly connected by the inner-layer signal through conductors 34 and the signal through conductor connecting conductors 33. Of the inner layers, the dielectric constant εr1 of the inner layer near the intermediate layer shown in 37 is formed as a layer smaller than the dielectric constant εr2 of the other layers.
[0021]
As a result, an electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion. As a result of this electromagnetic shielding space acting as a cylindrical dielectric resonator, the usable frequency band due to resonance Compared with the case where there is a restriction, the region where the inner ground conductor is not formed near the intermediate layer is reduced, so that it functions as a resonance control layer, that is, the cylindrical waveguide mode (TE11 mode) is cut off in the resonance control layer. As the frequency is higher than the cutoff frequency of the cylindrical waveguide mode (TE11 mode) of other layers, it is regarded as a reactance attenuator. As a result, high-order mode propagation is suppressed, and resonance according to the cylindrical dielectric resonance mode is In order to move to the high frequency side, the usable frequency band is widened. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0022]
Next, FIGS. 2 and 3 are views showing examples of the second laminated structure for high-frequency signal transmission according to claim 2 of the present invention, in which (a) is a plan view and (b) is a plan view. It is AA 'line sectional drawing of (a). In the first high-frequency signal transmission multilayer structure, the second high-frequency signal transmission multilayer structure surrounds the surface layer signal through conductor and the signal wiring connection conductor on the upper surface and / or the lower surface of the multilayer substrate. A surface ground conductor was formed at a predetermined interval with respect to the signal wiring conductor, and the surface ground conductor and the inner layer ground conductor were connected by a surface layer ground penetrating conductor extending vertically.
[0023]
2 and 3, the same reference numerals are assigned to the same parts as in FIG. 1, 1 is a dielectric layer, 11 and 21 are signal wiring conductors, 13 and 23 are signal wiring connecting conductors, 14 and 24 is a surface layer signal through conductor, 32 is an inner layer ground conductor, 33 is a signal through conductor connecting conductor, 34 is an inner layer signal through conductor, 35 is an inner layer ground through conductor, 36 is an inner layer ground conductor non-forming region, 37 is It is a resonance control layer. FIG. 2 shows that 12 surface ground conductors are formed at a predetermined interval with respect to the signal wiring conductor in a state of surrounding the surface signal through conductor 14 and the signal wiring connecting conductor 13 on the upper surface of the multilayer substrate; The surface ground conductor 12 and the inner layer ground conductor 32 are connected by 15 surface layer ground through conductors that penetrate vertically. FIG. 3 shows a state in which the surface signal through conductors 14 and 24 and the signal wiring connecting conductors 13 and 23 are surrounded on the upper and lower surfaces of the multilayer substrate by a predetermined distance from the signal wiring conductors 12 and 22, respectively. A surface ground conductor is formed, and the surface ground conductors 12 and 22 and the inner layer ground conductor 32 are connected by 15 and 25 surface layer ground through conductors passing vertically.
[0024]
As a result, an electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion. As a result of this electromagnetic shielding space acting as a cylindrical dielectric resonator, the usable frequency band due to resonance Compared with the case where the restriction occurs, it works as a resonance control layer because the dielectric constant near the intermediate layer is small, that is, the cutoff frequency of the cylindrical waveguide mode (TE11 mode) in the resonance control layer is the other layer Because it is considered as a reactance attenuator because it is higher than the cut-off frequency of the cylindrical waveguide mode (TE11 mode), higher-order mode propagation is suppressed. As a result, resonance according to the cylindrical dielectric resonance mode moves to the high-frequency side. Therefore, the usable frequency band is widened. In addition, by configuring as a coplanar line as an input / output line, when the external wiring is a coplanar line, the impedance discontinuity in connection with the external wiring can be reduced, and the resonance frequency is surface grounded. Compared with the case where the conductor and the surface layer grounding through conductor are not provided, the height increases as they are provided on one surface (corresponding to FIG. 2) and further on both surfaces (corresponding to FIG. 3). As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0025]
Next, FIG. 9 is a view showing another example of the second laminated structure for high-frequency signal transmission according to claim 3 of the present invention, in which (a) is a plan view and (b) is ( It is an AA 'line sectional view of a). Another example of the second laminated structure for high-frequency signal transmission is the surface grounding in the first laminated structure for high-frequency signal transmission with a predetermined distance from the signal wiring conductor on the upper surface and / or the lower surface of the laminated substrate. A conductor was formed, and the surface ground conductor and the inner layer ground conductor were connected by a surface layer ground through conductor that vertically penetrated.
[0026]
9, the same reference numerals are given to the same parts as in FIG. 1, 1 is a dielectric layer, 11 and 21 are signal wiring conductors, 13 and 23 are signal wiring connection conductors, and 14 and 24 are surface layers. Signal through conductor, 32 is an inner layer ground conductor, 33 is a signal through conductor connecting conductor, 34 is an inner layer signal through conductor, 35 is an inner layer ground through conductor, 36 is an inner layer ground conductor non-forming region, and 37 is a resonance control layer. It is. Then, on the upper surface of the multilayer substrate, 12 surface ground conductors are formed at a predetermined interval with respect to the signal wiring conductor 11, and 15 surface layers that vertically penetrate between the surface ground conductor 12 and the inner ground conductor 32 They are connected by a grounding through conductor.
[0027]
As a result, an electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion. As a result of this electromagnetic shielding space acting as a cylindrical dielectric resonator, the usable frequency band due to resonance Compared with the case where the restriction occurs, it works as a resonance control layer because the dielectric constant near the intermediate layer is small, that is, the cutoff frequency of the cylindrical waveguide mode (TE11 mode) in the resonance control layer is the other layer Because it is considered as a reactance attenuator because it is higher than the cut-off frequency of the cylindrical waveguide mode (TE11 mode), higher-order mode propagation is suppressed. As a result, resonance according to the cylindrical dielectric resonance mode moves to the high-frequency side. Therefore, the usable frequency band is widened. In addition, by configuring as a coplanar line as an input / output line, when the external wiring is a coplanar line, the impedance discontinuity in connection with the external wiring can be reduced, and the resonance frequency is surface grounded. Compared with the case where the conductor and the surface grounding through conductor are not provided, the height increases as the conductor is provided on one side (corresponding to FIG. 9) and further on both sides. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0028]
Further, the laminated structure for high frequency signal transmission can be applied to a high frequency semiconductor package. That is, a frame and a lid are formed on the upper surface of the multilayer substrate so as to accommodate the high-frequency semiconductor element, and an input / output signal wiring connection conductor for signal input / output with the outside is provided on the signal wiring conductor on the lower surface of the multilayer substrate. By forming, a high-frequency semiconductor package with good high-frequency transmission characteristics is obtained.
[0029]
  In such a high-frequency semiconductor package of the present invention, as the dielectric substrate, ceramic materials such as alumina, mullite, and aluminum nitride, so-called glassera (glass + ceramic) materials, are widely used, and conductors such as signal wiring conductors and ground conductors. The pattern is a metal material for a high-frequency wiring conductor, for example, a single metal such as Cu, MoMn + Ni + Au, W + Ni + Au, Cr + Cu, Cr + Cu + Ni + Au,Ta ₂ NIt is formed by a thick film printing method or various thin film forming methods or plating methods using an alloy such as + NiCr + Au, Ti + Pd + Au, NiCr + Pd + Au. Further, the thickness and width are set together with the dielectric constant and thickness of the dielectric according to the frequency of the transmitted high-frequency signal, the characteristic impedance used, and the like. Moreover, when using a metal for a frame or a lid, Fe-Ni alloy such as Fe-Ni-Co and Fe-Ni42 alloy, oxygen-free copper, aluminum, stainless steel, Cu-W alloy, Cu-Mo alloy, etc. It is hermetically sealed by bonding with a high melting point metal solder such as solder, AuSn solder, AuGe solder, or seam weld (welding) for joining between metal structures. The substrate and the metal structure are joined by a high melting point metal brazing such as AgCu solder, AuSn solder, or AuGe solder, so that a high frequency semiconductor package having good transmission characteristics can be provided by accommodating a semiconductor element.
[0030]
【Example】
Next, a specific example of the laminated structure for high frequency signal transmission according to the present invention will be described.
[0031]
First, the dielectric layer 1 has a relative dielectric constant of 10 with the same configuration as that of FIG. 3 showing the laminated structure for high-frequency signal transmission according to claim 3 of the present invention, but the relative dielectric constant of the resonance control layer 37 is 8.5. Nine layers with a thickness of 0.2 mm are laminated to form a laminated plate, the line width of the signal wiring conductors 11 and 21 on the top and bottom surfaces is 0.14 mm, the width of the signal wiring conductor 11 on the inner layer is 0.21 mm, and The signal wiring connection conductors 13 and 23 have a line width of 0.16 mm, the inner layer signal wiring connection conductors 13 and 23 have a width of 0.21 mm, and the distance between the signal wiring conductors 11 and 21 and the surface signal through conductors 14 and 24 is as follows. 0.13 mm, surface signal through conductors 14 and 24 and inner layer signal through conductor 34 have a circular shape with a diameter of 0.1 mm, signal through conductor connecting conductor has a rectangular shape with a width of 0.16 mm, and inner layer ground inner layer ground conductor is not formed The region 36 has a circular shape with a diameter of 1.24 mm, and the inner-layer grounding through conductor 35 has a circular shape with a diameter of 0.1 mm, and the center is 0 from the outer periphery of the inner-layer grounding conductor non-forming region 36. It is configured by arranging it at 8 places on the circumference separated by .08mm, and the upper and lower surfaces surround inner surface signal through conductors 14 and 24 and signal wiring connection conductors 13 and 23. The surface ground conductors 12 and 22 are formed at a distance of 0.10 mm from the signal wiring conductors 11 and 21 so as to match the shape with the non-forming region 36, and the surface ground conductors 12 and 22 and the inner layer ground conductor 32 Are connected by through-surface grounding through conductors 15 and 25 having a diameter of 0.1 mm extending vertically between them, and the displacement between the 9 layers of the surface signal through conductors 14 and 24 and the inner layer signal through conductor 34 is 0.195 mm and 0.115 from the surface side. mm, 0.075mm, 0.055mm, 0.055mm, 0.075mm, 0.115mm, 0.195mm, and 2.0mm when viewed from above between the ends of the signal wiring conductors 11 and 21 on the opposite side of the signal wiring connection conductors 13 and 23 By setting the relative dielectric constant of the resonance control layer 37 to 8.5, a sample A having a laminated structure for high-frequency signal transmission according to the present invention was obtained. Similarly to the sample A, except that the relative dielectric constant of the resonance control layer 37 was set to 6 to obtain a sample B having a laminated structure for high-frequency signal transmission according to the present invention.
[0032]
Further, in the same configuration as that of FIG. 7 showing the laminated structure for high-frequency signal transmission as a comparative example, no resonance control layer is provided for the sample A, and the relative dielectric constant of the resonance control layer 37 is the same in all layers. Thus, a sample C having a laminated structure for high frequency signal transmission as a comparative example was obtained.
[0033]
When the electrical characteristics between the ends of the signal wiring conductor 21 on the lower surface and the ends of the signal wiring conductor 11 on the upper surface of these samples A, B, and C are extracted by electromagnetic field simulation, they are shown in a diagram in FIG. A characteristic curve with such a frequency characteristic was obtained. In FIG. 4, the horizontal axis indicates the frequency (unit: GHz), the vertical axis indicates the reflection coefficient (unit: dB) as an evaluation index of the reflected amount of the input signal, and the characteristic curve indicates the reflection coefficient. The frequency characteristics are shown. Further, A, B, and C added to the characteristic curve indicate that they are characteristic curves of the samples A, B, and C, respectively.
[0034]
From this result, the sample B which is the laminated structure for high frequency signal transmission of the present invention has a resonance frequency of 54.8 GHz, and the sample A which is the laminated structure for high frequency signal transmission of the present invention has a resonance frequency of 56.0 GHz. As a comparative example, the resonant frequency of sample C, which is a laminated structure for high-frequency signal transmission, is 53.8 GHz, whereas the resonant frequency has moved to the high-frequency side, and the laminated structure for high-frequency signal transmission that has been made wider. I know that there is. In particular, the tendency is remarkable in the sample A having the smallest dielectric constant of the resonance control layer 37, and a wider band has been achieved.
[0035]
In addition, the above is an illustration of embodiment of this invention to the last, This invention is not limited to these, A various change and improvement can be added in the range which does not deviate from the summary of this invention.
[0036]
For example, in the embodiment of the present invention, the resonance control layer is one layer and has the same thickness as the other layers. However, a plurality of layers may be used, and the thickness of the resonance control layer may be the same as the thickness of the other layers. Even if the thickness is different, the same effect can be obtained. However, if the number of layers provided as the resonance control layer increases, the transmission distance increases, so the reactance attenuation amount increases.Therefore, the cutoff effect can be expected, but if the distance becomes too long, the frequency up to the cutoff frequency Since the decrease in characteristic impedance appears remarkably due to the increase in capacitance, there is an adverse effect of increasing reflection. Therefore, the distance, that is, the thickness of the layer provided as the resonance control layer may be appropriately determined.
[0037]
【The invention's effect】
  As described above, according to the laminated structure for high-frequency signal transmission according to claim 1, the signal wiring conductors formed on the uppermost layer and the lowermost layer of the laminated substrate formed by laminating four or more dielectric layers are mutually connected. Connects one end of each signal wiring conductor to the uppermost layer and the lowermost dielectric layer through the signal wiring connecting conductor, extending in the opposite direction from one end. In each of the inner layers excluding the uppermost layer and the lowermost layer, the planar shape isCircular or elliptical shapeAn inner-layer ground conductor non-forming region and an inner-layer ground conductor are formed, and in the inner-layer ground conductor non-forming region, a signal through-conductor connecting conductor is connected to an inner-layer signal through-conductor that vertically penetrates each layer of the inner layer. Forming an outer periphery of the inner-layer ground conductor non-forming regionOutsideIn addition, the inner layer grounding conductors are connected by forming inner layer grounding through conductors that vertically penetrate each inner layer, and the surface signal through conductors are shortened so that the length of the signal wiring connecting conductors is reduced. The outer periphery of the inner layer ground conductor non-formation regionInsideThe inner layer signal through conductors are sequentially shifted so that the surface layer signal through conductors are smoothly connected, and the dielectric constant of the layer located in the middle of each of the inner layers, Since the electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion because it is smaller than the other layers, the electromagnetic shielding space acts as a cylindrical dielectric resonator. Compared with the case where the usable frequency band is restricted due to resonance, the dielectric constant in the vicinity of the intermediate layer is reduced, so that it functions as a resonance control layer, that is, a cylindrical waveguide mode (TE11 mode in the resonance control layer). ) Is higher than the cutoff frequency of the cylindrical waveguide mode (TE11 mode) of the other layer, so that it is regarded as a reactance attenuator. Results There are suppressed, resonance in conformity with the cylindrical dielectric resonator mode to move to the high frequency side, the available frequency band is widened. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0038]
According to the multilayer structure for high-frequency signal transmission according to claim 2, in the multilayer structure for high-frequency signal transmission according to claim 1, the surface signal penetration conductor and the signal wiring connection on the upper surface and / or the lower surface of the multilayer substrate. In a state surrounding the conductor, a surface ground conductor is formed at a predetermined interval with respect to the signal wiring conductor, and the surface ground conductor and the inner layer ground conductor are connected by a surface layer ground penetrating conductor extending vertically. Therefore, since the electromagnetic shielding space surrounded by the inner layer ground conductor and the inner layer grounding through conductor is formed in the inner layer portion, the electromagnetic shielding space works as a cylindrical dielectric resonator, and as a result, the usable frequency band due to resonance. Compared to the case where there is a limitation of the Since the cut-off frequency of the tube mode (TE11 mode) is higher than the cut-off frequency of the cylindrical waveguide mode (TE11 mode) of other layers, it is regarded as a reactance attenuator. Since the resonance according to the body resonance mode moves to the high frequency side, the usable frequency band is widened. In addition, by configuring as a coplanar line as an input / output line, when the external wiring is a coplanar line, the impedance discontinuity in connection with the external wiring can be reduced, and the resonance frequency is surface grounded. Compared to the case where the conductor and the surface layer grounding through conductor are not provided, the height becomes higher as the conductor is provided on one side and further on both sides. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0039]
According to the multilayer structure for high-frequency signal transmission according to claim 3, in the multilayer structure for high-frequency signal transmission according to claim 1, a predetermined interval is provided with respect to the signal wiring conductor on the upper surface and / or the lower surface of the multilayer substrate. Since the surface ground conductor is formed and the surface ground conductor and the inner layer ground conductor are connected by the surface layer ground through conductor that passes vertically, the inner layer portion is surrounded by the inner layer ground conductor and the inner layer ground through conductor. As a result of this electromagnetic shielding space being formed, this dielectric shielding space acts as a cylindrical dielectric resonator, resulting in a lower dielectric constant in the vicinity of the intermediate layer than when the usable frequency band is restricted due to resonance. Therefore, the cutoff frequency of the cylindrical waveguide mode (TE11 mode) in the resonance control layer is the cylindrical waveguide mode (TE11) of the other layer. Since the higher-order mode propagation is suppressed because it is considered to be a reactance attenuator because it is higher than the cutoff frequency, the resonance according to the cylindrical dielectric resonance mode moves to the high frequency side, so that it can be used. Bandwidth becomes wider. In addition, by configuring as a coplanar line as an input / output line, when the external wiring is a coplanar line, the impedance discontinuity in connection with the external wiring can be reduced, and the resonance frequency is surface grounded. Compared with the case where the conductor and the surface grounding through conductor are not provided, the height increases as the conductor is provided on one side (corresponding to FIG. 9) and further on both sides. As a result, a laminated structure for high-frequency signal transmission in which the usable frequency band is widened is obtained.
[0040]
Further, according to the high-frequency semiconductor package of claim 4, for example, the frame and the lid are formed so as to accommodate the high-frequency semiconductor element on the upper surface of the laminated substrate having the laminated structure for high-frequency signal transmission of claims 1 to 2. By forming the input / output signal wiring connection conductor for signal input / output with the outside on the signal wiring conductor on the lower surface of the multilayer substrate, it can be provided as a high-frequency semiconductor package having good high-frequency transmission characteristics.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an example of a first laminated structure for high-frequency signal transmission according to the present invention, where (a) is a plan view and (b) is a cross-sectional view taken along line AA ′ of (a). It is.
2A and 2B are diagrams schematically showing an example of a second laminated structure for high-frequency signal transmission according to the present invention, where FIG. 2A is a plan view, and FIG. 2B is a cross-sectional view taken along line AA ′ in FIG. It is.
3A and 3B are diagrams schematically showing an example of a second laminated structure for high-frequency signal transmission according to the present invention, in which FIG. 3A is a plan view, and FIG. 3B is a cross-sectional view taken along line AA ′ in FIG. It is.
FIG. 4 is a diagram comparing high-frequency characteristics of a second high-frequency signal transmission multilayer structure of the present invention and a high-frequency signal transmission multilayer structure as a comparative example.
FIG. 5 is a plan view and a cross-sectional view showing a comparative example of a laminated structure for high-frequency signal transmission.
FIGS. 6A and 6B are a plan view and a cross-sectional view showing another comparative example of a laminated structure for high-frequency signal transmission. FIGS.
7A and 7B are a plan view and a cross-sectional view showing still another comparative example of the laminated structure for high-frequency signal transmission.
FIG. 8 is a diagram showing a high-frequency characteristic example of a laminated structure for high-frequency signal transmission (comparative example).
9 is a diagram schematically showing another example of the second laminated structure for high-frequency signal transmission according to the present invention, where (a) is a plan view and (b) is an AA ′ line in (a). FIG. It is sectional drawing.
[Explanation of symbols]
1 ... Dielectric layer
11,21 ・・・・・ Signal wiring conductor
12,22 ・・・・・ Surface ground conductor
13,23 ・・・・・ Signal connection conductor
14,24 ... Surface signal through conductor
15,25 ・・・・・ Through-surface grounding conductor
16,26 ・・・・・ surface ground conductor non-formation area
32 ・・・・・ Inner layer ground conductor
33 ・・・・・ Signal through conductor connection conductor
34 ・・・・・ Inner signal through-conductor
35 ・・・・・ Through-hole through conductor for inner layer grounding
36 ・・・・・ Inner layer ground conductor non-formation area
37 ・・・・・ Resonance control layer

Claims

The signal wiring conductors formed on the uppermost layer and the lowermost layer of the multilayer substrate formed by laminating four or more dielectric layers are in a relationship extending in the opposite direction from one end, and one end of each of these signal wiring conductors, The top layer and the lower layer dielectric layer are vertically connected to each other through a signal wiring connecting conductor, and each of the inner layers excluding the uppermost layer and the lowermost layer has a planar shape. An inner layer ground conductor non-forming region having a circular shape or an ellipse shape and an inner layer ground conductor are formed, and in the inner layer ground conductor non-forming region, a signal connected to an inner layer signal through conductor that vertically penetrates each layer of the inner layer Forming a through-conductor connecting conductor, and connecting the inner-layer ground conductors by forming inner-layer grounding through conductors that vertically penetrate each layer of the inner layer outside the outer periphery of the inner-layer ground conductor non-forming region, Surface signal penetration With placing the conductor on the inner side of the outer periphery of the inner layer ground conductor non-formation region, and arranged sequentially shifted to between the inner layer signal through conductor said surface layer signal through conductor is connected, the layers forming the inner layer A laminated structure for high-frequency signal transmission, characterized in that the dielectric constant of the middle layer is lower than that of the other layers.

On the upper surface and / or lower surface of the multilayer substrate, a surface ground conductor is formed at a predetermined interval from the signal wiring conductor in a state of surrounding the surface signal through conductor and the signal wiring connecting conductor, and the surface 2. The laminated structure for high-frequency signal transmission according to claim 1, wherein the ground conductor and the inner-layer ground conductor are connected by a surface-layer grounding through conductor that passes vertically.

On the upper surface and / or the lower surface of the multilayer substrate, a surface ground conductor is formed at a predetermined interval with respect to the signal wiring conductor, and a surface layer ground penetration vertically penetrates between the surface ground conductor and the inner layer ground conductor. The laminated structure for high-frequency signal transmission according to claim 1, wherein the laminated structure is connected by a conductor.

A structure is provided in which a high-frequency semiconductor element is accommodated by providing a frame body and a lid on the upper surface of the multilayer substrate including the multilayer structure for high-frequency signal transmission according to any one of claims 1 to 3. High frequency semiconductor package.