JPH09321569A - Board mounting method for saw filter - Google Patents

Board mounting method for saw filter

Info

Publication number
JPH09321569A
JPH09321569A JP13699396A JP13699396A JPH09321569A JP H09321569 A JPH09321569 A JP H09321569A JP 13699396 A JP13699396 A JP 13699396A JP 13699396 A JP13699396 A JP 13699396A JP H09321569 A JPH09321569 A JP H09321569A
Authority
JP
Japan
Prior art keywords
gnd
electrode
land
output
input
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP13699396A
Other languages
Japanese (ja)
Other versions
JP3895397B2 (en
Inventor
Hiromi Yatsuda
博美 谷津田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Japan Radio Co Ltd
Original Assignee
Japan Radio Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Japan Radio Co Ltd filed Critical Japan Radio Co Ltd
Priority to JP13699396A priority Critical patent/JP3895397B2/en
Publication of JPH09321569A publication Critical patent/JPH09321569A/en
Application granted granted Critical
Publication of JP3895397B2 publication Critical patent/JP3895397B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0213—Electrical arrangements not otherwise provided for
    • H05K1/0237—High frequency adaptations
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/18—Printed circuits structurally associated with non-printed electric components

Landscapes

  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

PROBLEM TO BE SOLVED: To improve the characteristic of the SAW filter. SOLUTION: An incremental/decremental inductance ΔLg is taken into account for a common inductance Lg with respect to GND attended with mounting of the SAW filter onto a board by utilizing a conductor pattern and a throughhole or the like of a printed circuit board on which the SAW filter is to be mounted. Or similarly an incremental/decremental capacitance ΔCc is taken into account through a means such as a pattern change. A frequency trap having been produced at a comparatively higher frequency band based on the pass characteristic of the SAW filter is shifted in the vicinity of the pass-band through the addition of the ΔLg or ΔCc and then the block band attenuation in the vicinity of the pass-band is improved.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、回路基板上に実装
可能な弾性表面波（ＳＡＷ）フィルタに関し、特にその
基板実装方法の改良による特性の改善に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave (SAW) filter that can be mounted on a circuit board, and more particularly to improvement of characteristics by improving the board mounting method.

【０００２】[0002]

【従来の技術】従来から、通信機器等において各種のＳ
ＡＷデバイスが用いられている。ＳＡＷデバイスは、水
晶、ニオブ酸リチウム、タンタル酸リチウム等圧電性を
有する素材の基板の表面に、この基板を励振するための
電極を配置形成したデバイスである。例えばＳＡＷフィ
ルタにおいては、一般に、入力電極及びこれと対を成す
ＧＮＤ電極と、出力電極及びこれと対を成すＧＮＤ電極
とが、圧電性基板の同一の面上に、かつＳＡＷ伝搬方向
に沿って並んで、配置される。入力電極及びこれと対を
成すＧＮＤ電極の間に電気信号が印加されると、この電
気信号のうち電極構造にて定まるある特定の周波数成分
が機械振動に変換される（電気音響変換）。電気音響変
換にて発生した振動のうち、出力電極及びこれと対を成
すＧＮＤ電極まで顕著な減衰なしで到達できるのは、使
用する基板の材質及びそのカットの選択や基板表面の電
極被覆状況等により定まるある特定のモードの波のみで
あり、ＳＡＷフィルタでは基板の表面又は比較的浅い部
位を伝搬するモードの波（これらを総称してＳＡＷと呼
ぶ）を利用する。出力電極及びこれと対を成すＧＮＤ電
極においては、伝搬してきた波のうちその電極構造にて
定まるある特定の周波数成分が、電気信号に変換される
（音響電気変換）。ＳＡＷフィルタは、上に例示した素
材の基板を用いその基板の上で上述の電気音響変換、Ｓ
ＡＷ伝搬及び音響電気変換を実行することを特徴とする
フィルタであり、単一面上における電極配置・電極構造
のみによってその特性が原理上概ね定まること、電極設
計・製造に半導体関連技術を応用できること、マイクロ
プロセスの利用によりその通過帯域をＶＨＦ〜ＵＨＦと
いった高周波域に設定できるため無線通信機器のＲＦ回
路等を含め広い用途に対応できること等の利点を有して
いる。2. Description of the Related Art Conventionally, various S's have been used in communication equipment.
AW devices are used. The SAW device is a device in which electrodes for exciting the substrate are arranged and formed on the surface of a substrate made of a material having piezoelectricity such as quartz, lithium niobate, and lithium tantalate. For example, in a SAW filter, generally, an input electrode and a GND electrode paired with it, an output electrode and a GND electrode paired with this are on the same surface of the piezoelectric substrate and along the SAW propagation direction. They are placed side by side. When an electric signal is applied between the input electrode and the GND electrode forming a pair with the input electrode, a specific frequency component determined by the electrode structure of the electric signal is converted into mechanical vibration (electroacoustic conversion). Of the vibrations generated by electroacoustic conversion, it is possible to reach the output electrode and the GND electrode that forms a pair with the output electrode without noticeable attenuation, such as the selection of the substrate material to be used and its cut, and the electrode coating condition on the substrate surface. The SAW filter uses a wave of a mode propagating on the surface of the substrate or a relatively shallow portion (these are collectively referred to as SAW). In the output electrode and the GND electrode forming a pair with the output electrode, a specific frequency component determined by the electrode structure of the propagating wave is converted into an electric signal (acoustoelectric conversion). The SAW filter uses a substrate made of the above-exemplified material, and the electroacoustic conversion, S
It is a filter characterized by performing AW propagation and acoustoelectric conversion, its characteristics are basically determined in principle only by the electrode arrangement / electrode structure on a single surface, that semiconductor-related technology can be applied to electrode design / manufacturing, Since the pass band can be set to a high frequency range such as VHF to UHF by using the micro process, it has an advantage that it can be applied to a wide range of applications including an RF circuit of a wireless communication device.

【０００３】図１１に、ＳＡＷフィルタの一例としてい
わゆる多電極型ＳＡＷフィルタを示す。この図のフィル
タは、上述の素材から形成されたＳＡＷ基板１０の同一
面上に、入力電極１４ＴとＧＮＤ電極１４Ｇの対（以下
これを入力電極対１２Ｔと呼ぶ）及び出力電極１４Ｒと
ＧＮＤ電極１４Ｇの対（以下これを出力電極対１２Ｒと
呼ぶ）を、ＳＡＷ伝搬方向に沿って複数個交互にかつほ
ぼ平行に並設した構成を有している。電極１４Ｔ、１４
Ｒ及び１４Ｇはいずれも櫛歯状の電極構成、すなわち所
定幅所定長の指状電極を所定間隔で並べ各指状電極の一
端を互いに接続した構成を有している。入力電極１４Ｔ
又は出力電極１４Ｒとこれに対応するＧＮＤ電極１４Ｇ
は、等間隔で指交叉状に、即ち指状電極がちょうど両手
の指を組んだのと同じような形をなすよう配置されてい
る（インターディジタル配置）。電極対１２Ｔ及び１２
Ｒは、大まかには、構造、形状、寸法等を含め互いに同
一の構成を有しているが、厳密には、要求特性を実現す
る必要上両者の構成を若干異なる構成としたり、指状電
極の幅、長さ、間隔に不均一さを導入したり、指状電極
を間引くことがある。また、図示の簡略化のため、指状
電極の本数を実際より極めて少なく（従って間隔は非常
に広めに）表していることにも留意されたい。更に、複
数個の入力電極対１２Ｔに同一の電気信号を供給しまた
複数個の出力電極対１２Ｒからの電気信号を合成結合す
る必要上、入力電極１４Ｔを共通接続導体１６Ｔにて、
出力電極１４Ｒを共通接続導体１６Ｒにて、ＧＮＤ電極
１４Ｇを共通接続導体１６Ｇにて、互いに接続してい
る。共通接続導体１６Ｔ、１６Ｒ及び１６Ｇはいずれも
ＳＡＷ基板１０の表面に被着形成する。FIG. 11 shows a so-called multi-electrode type SAW filter as an example of the SAW filter. The filter of this figure has a pair of an input electrode 14T and a GND electrode 14G (hereinafter referred to as an input electrode pair 12T) and an output electrode 14R and a GND electrode 14G on the same surface of the SAW substrate 10 formed of the above-mentioned material. A plurality of pairs (hereinafter referred to as output electrode pairs 12R) are arranged in parallel and alternately in parallel along the SAW propagation direction. Electrodes 14T, 14
Each of R and 14G has a comb-tooth-shaped electrode structure, that is, a structure in which finger electrodes having a predetermined width and a predetermined length are arranged at predetermined intervals and one ends of the finger electrodes are connected to each other. Input electrode 14T
Alternatively, the output electrode 14R and the corresponding GND electrode 14G
Are arranged at equal intervals in a finger-crossed shape, that is, the finger-shaped electrodes have a shape similar to that of fingers of both hands (interdigital arrangement). Electrode pair 12T and 12
R roughly has the same configuration including the structure, shape, dimensions, etc., but strictly speaking, in order to achieve the required characteristics, the configurations of the two may be slightly different from each other, or the finger-like electrodes may be formed. May introduce non-uniformity in the width, length and spacing of the electrodes, or thin out the finger electrodes. It should also be noted that, for simplicity of illustration, the number of finger electrodes is shown to be much smaller than it really is (thus the spacing is very wide). Further, since it is necessary to supply the same electric signal to the plurality of input electrode pairs 12T and to combine and combine the electric signals from the plurality of output electrode pairs 12R, the input electrode 14T is connected by the common connection conductor 16T.
The output electrode 14R is connected to the common connection conductor 16R, and the GND electrode 14G is connected to the common connection conductor 16G. All of the common connection conductors 16T, 16R, and 16G are formed by depositing on the surface of the SAW substrate 10.

【０００４】図１１に示されるＳＡＷフィルタを実際に
回路上で使用するためには、これを、回路基板上に実装
可能なパッケージに収納する必要がある。図１２に、パ
ッケージ２０に収納されたＳＡＷフィルタの外観の一例
を示す。この図に示されているパッケージ２０は表面実
装型の方形パッケージ即ち回路基板の表面にピン等なし
で実装可能な方形のパッケージであり、その下面（フッ
トプリント）の隅部には導電部材からなる入力端子２２
Ｔ、出力端子２２Ｒ及びＧＮＤ端子２２Ｇが設けられて
いる。図１１に示されるＳＡＷ基板１０は、このパッケ
ージ２０の内部に収納かつ固定されており、また、入力
電極１４Ｔ、出力電極１４Ｒ及びＧＮＤ電極１４Ｇはパ
ッケージ内部の配線（図示せず）を介してそれぞれ端子
２２Ｔ、２２Ｒ又は２２Ｇに接続されている。In order to actually use the SAW filter shown in FIG. 11 on a circuit, it must be housed in a package mountable on a circuit board. FIG. 12 shows an example of the appearance of the SAW filter housed in the package 20. The package 20 shown in this figure is a surface-mounting type rectangular package, that is, a rectangular package that can be mounted on the surface of a circuit board without pins or the like, and is made of a conductive material at the corners of its lower surface (footprint). Input terminal 22
T, an output terminal 22R and a GND terminal 22G are provided. The SAW substrate 10 shown in FIG. 11 is housed and fixed inside the package 20, and the input electrode 14T, the output electrode 14R, and the GND electrode 14G are respectively connected via wiring (not shown) inside the package. It is connected to the terminals 22T, 22R or 22G.

【０００５】この接続を実現する手法としては、“パッ
ケージ２０内部に設けられた収納孔にＳＡＷ基板１０を
収納かつ固定した後、収納孔近傍に設けられている入
力、出力及びＧＮＤの各パッドに電極１４Ｔ、１４Ｒ及
び１４Ｇ（又はこれら各々に係る共通接続導体）をワイ
ヤボンディング等の方法で接続し、更にこれらのパッド
をパッケージ２０を貫通する配線を介し端子２２Ｔ、２
２Ｒ又は２２Ｇのうち対応するものに接続する”、とい
う方法を用いることができる。あるいは、“パッケージ
２０内部に設けられた収納孔の底面に入力、出力及びＧ
ＮＤの各パッドを特定のパターンで設けておき、電極１
４Ｔ、１４Ｒ及び１４Ｇ（又はこれら各々に係る共通接
続導体）がこれら収納孔底面上のパッドのうち対応する
ものと対向するよう位置決めしながらＳＡＷ基板１０を
当該底面に向けフェースダウンボンディングし、収納孔
底面上のパッドを更にパッケージ２０を貫通する配線を
介し端子２２Ｔ、２２Ｒ又は２２Ｇのうち対応するもの
に接続する”、という方法を用いることができる。後者
の方法を使用した場合、収納孔底面のパッドのパターン
によっては、共通接続導体１６Ｇを省略できる。As a method for realizing this connection, "the SAW substrate 10 is housed and fixed in a housing hole provided inside the package 20, and then the input, output and GND pads provided in the vicinity of the housing hole are connected to each pad. The electrodes 14T, 14R and 14G (or common connection conductors associated with each of them) are connected by a method such as wire bonding, and further, these pads are connected to terminals 22T, 2 through wirings penetrating the package 20.
2R or 22G, the corresponding one can be used. ”Alternatively,“ input, output and G are provided on the bottom surface of the storage hole provided inside the package 20.
Each pad of ND is provided in a specific pattern, and the electrode 1
4T, 14R, and 14G (or common connection conductors associated with each of them) are positioned so that they face the corresponding pads on the bottom surface of these storage holes, and the SAW substrate 10 is face-down-bonded toward the bottom surface to form the storage holes. The pad on the bottom surface is further connected to the corresponding one of the terminals 22T, 22R or 22G through the wiring penetrating the package 20 ". When the latter method is used, The common connection conductor 16G may be omitted depending on the pad pattern.

【０００６】図１３に、図１２のＳＡＷフィルタを回路
基板３０特にそのＧＮＤ面上に実装する方法の一例を示
す。回路基板３０の図中上側の面（この場合ＧＮＤ面）
には入力端子２２Ｔ及び出力端子２２Ｒに対応する導電
性のランドとして入力ランド３２Ｔ及び出力ランド３２
Ｒが被着形成されている。この面のそれ以外の部位は、
導電性のＧＮＤパターン３４Ｇによって被覆されてい
る。ＳＡＷフィルタを実装するに際しては、端子２２Ｔ
及び２２Ｒがそれぞれランド３２Ｔ又は３２Ｒに対向す
るよう位置決めした上で、端子２２Ｔ及び２２Ｒを３２
Ｔ又は３２Ｒに、また端子２２ＧをＧＮＤパターン３４
Ｇに、いずれも半田、導電性接着剤等を用いて電気的に
接続する。なお、ランド３２Ｔ及び３２ＲとＧＮＤパタ
ーン３４Ｇとの間には、両者の電気絶縁を維持すべく、
導電部材の存在しないギャップ３６Ｔ及び３６Ｇが形成
されている。ランド３２Ｔ及び３２Ｒやギャップ３６Ｔ
及び３６Ｇの形状・寸法は、端子２２Ｔ及び２２Ｒが対
応するランド（３２Ｔ又は３２Ｒ）以外の部位と接触乃
至結合しないよう設定する。また、回路基板３０の図中
下側の面（この場合部品実装面）には、他の回路部品
（例えばＲＦ増幅器や整合回路等）が実装されており、
更にこれらの回路部品とＳＡＷフィルタとを接続するた
めの導電パターンが形成されている（図示せず）。ラン
ド３２Ｔ及び３２Ｒには、この導電パターンと端子２２
Ｔ及び２２Ｒとを接続するため、その内部に導電材料が
充填乃至配置されたスルーホール３８が形成されてい
る。FIG. 13 shows an example of a method for mounting the SAW filter shown in FIG. 12 on the circuit board 30, especially on the GND surface thereof. The upper surface of the circuit board 30 in the drawing (in this case, the GND surface)
The input land 32T and the output land 32 are conductive lands corresponding to the input terminal 22T and the output terminal 22R.
R is adhered and formed. The other parts of this surface are
It is covered with the conductive GND pattern 34G. When mounting the SAW filter, the terminal 22T
And 22R are positioned so as to face the lands 32T or 32R, respectively, and then the terminals 22T and 22R are set to 32.
T or 32R, and the terminal 22G to the GND pattern 34
All are electrically connected to G using solder, a conductive adhesive, or the like. In addition, between the lands 32T and 32R and the GND pattern 34G, in order to maintain electrical insulation between them,
Gap 36T and 36G where no conductive member is present are formed. Land 32T and 32R and gap 36T
The shapes and dimensions of 36G and 36G are set so that the terminals 22T and 22R do not come into contact with or be coupled to a portion other than the corresponding land (32T or 32R). Further, other circuit components (for example, an RF amplifier, a matching circuit, etc.) are mounted on the lower surface of the circuit board 30 (in this case, the component mounting surface),
Further, a conductive pattern for connecting these circuit components and the SAW filter is formed (not shown). The conductive patterns and the terminals 22 are provided on the lands 32T and 32R.
In order to connect T and 22R, a through hole 38 filled or arranged with a conductive material is formed therein.

【０００７】実装方法としては、図１３とは逆に、部品
実装面にＳＡＷフィルタを実装する方法がある。即ち、
“回路基板３０の部品実装面に、他の回路部品との接続
用の導電パターンの他にＧＮＤランドを設けておき、実
装に当たっては他の回路部品との接続用の導電パターン
にランド３２Ｔ及び３２Ｒをまた当該ＧＮＤランドに端
子２２Ｇをそれぞれ接続し、ＧＮＤ面のＧＮＤパターン
３４Ｇと当該ＧＮＤランドの間はスルーホール等で接続
する”、という方法も考えられる。しかし、この方法
は、ＧＮＤ間共通インピーダンスの発生の点で、図１３
の方法より劣っている。即ち、部品実装面上のＧＮＤラ
ンドとＧＮＤ面上のＧＮＤパターン３４Ｇとを接続する
ために使用するスルーホールによって意図しないインピ
ーダンスが発生し、このインピーダンスを介しＳＡＷフ
ィルタの入出力間が不正常に結合してしまうため、意図
した特性を得にくくなる。As a mounting method, contrary to FIG. 13, there is a method of mounting a SAW filter on the component mounting surface. That is,
“A GND land is provided on the component mounting surface of the circuit board 30 in addition to a conductive pattern for connection with other circuit components, and in mounting, lands 32T and 32R are formed on the conductive pattern for connection with other circuit components. It is also possible to connect the terminals 22G to the GND lands and connect the GND patterns 34G on the GND surface to the GND lands with through holes or the like ”. However, this method is different from that shown in FIG.
Is inferior to the method. That is, an unintended impedance is generated due to the through hole used to connect the GND land on the component mounting surface to the GND pattern 34G on the GND surface, and the input and output of the SAW filter are incorrectly coupled through this impedance. Therefore, it becomes difficult to obtain the intended characteristics.

【０００８】図１３の方法によれば、端子２２ＧとＧＮ
Ｄパターン３４Ｇとがスルーホールを介さずに接続され
るためこのような意図しないインピーダンスは発生しに
くい。しかし、この方法によっても、ＧＮＤ間共通イン
ピーダンスを完全には排除できず、従って、従来は、し
ばしば、要求特性からはずれた特性しか実現できない状
況が存していた。According to the method of FIG. 13, the terminals 22G and GN are
Since the D pattern 34G is connected without passing through the through hole, such an unintended impedance is unlikely to occur. However, even with this method, it is not possible to completely eliminate the common impedance between GNDs, and therefore, conventionally, there have often been situations in which only characteristics deviating from the required characteristics can be realized.

【０００９】[0009]

【発明の概要】本発明の発明者は、ＧＮＤ間共通インピ
ーダンス等の入出力間二次結合が、ＳＡＷフィルタの実
際の特性にどのような影響を与えるのか、即ち設計時に
等価回路シミュレーション等により予測した特性から実
際の特性をどの様にずらしてしまうのか、に関し、定量
的な検討を行った。SUMMARY OF THE INVENTION The inventor of the present invention predicts how the secondary coupling between input and output such as common impedance between GND affects the actual characteristics of a SAW filter, that is, predicts it by equivalent circuit simulation at the time of design. A quantitative study was conducted on how the actual characteristics are deviated from the above characteristics.

【００１０】この検討の第１段階として、発明者は、８
００ＭＨｚ帯に通過帯域を有するＳＡＷフィルタに関
し、その通過帯域を測定すると共に、その設計情報に基
づく等価回路シミュレーションを実施した。等価回路シ
ミュレーションの際には、従来周知の等価回路モデルを
用いた。実測の結果を図１に、数値シミュレーションの
結果を図２に、それぞれ示す。一見して明らかなよう
に、両者の間には、特に通過帯域外に関し、大きな相違
が生じている。As the first step of this examination, the inventor
Regarding a SAW filter having a pass band in the 00 MHz band, the pass band was measured and an equivalent circuit simulation based on the design information was performed. In the equivalent circuit simulation, a conventionally known equivalent circuit model was used. The result of the actual measurement is shown in FIG. 1, and the result of the numerical simulation is shown in FIG. As is apparent at first glance, there is a great difference between the two, especially in the outside of the pass band.

【００１１】検討の第２段階として、発明者は、ＧＮＤ
間共通インピーダンス以外に入出力間二次結合につなが
る要素はないか、またこれを含め入出力間二次結合につ
ながる要素を等価回路表現したときどの様な回路となる
か、に関して検討を行った。その結果得られた等価回路
モデルを図３に示す。この図中の“ＳＡＷ”は、図２の
等価回路シミュレーションの基礎となった従来の等価回
路モデル（即ち入出力間二次結合を考慮していないとき
のＳＡＷフィルタの伝達関数）を示すブロックである。
インダクタンスＬｇは上述のＧＮＤ間共通インピーダン
スを表すものであり、容量Ｃｃは入力電極１４Ｔ・出力
電極１４Ｒ間の容量結合を表すものである。ここでは、
端子２２Ｇ、ＧＮＤパターン３４Ｇ及び両者を接続する
半田等の抵抗値が十分小さいという実際的な仮定の下
に、ＧＮＤ間共通インピーダンスをＧＮＤ間共通インダ
クタンスＬｇにて表している。As the second stage of the study, the inventor
We examined whether there are any elements other than the common impedance between the inputs and outputs that are connected to the secondary coupling between the input and output, and what kind of circuit it would be if the elements connected to the secondary connection between the input and output are expressed as an equivalent circuit. . The equivalent circuit model obtained as a result is shown in FIG. “SAW” in this figure is a block showing the conventional equivalent circuit model (that is, the transfer function of the SAW filter when the quadratic coupling between the input and output is not considered) which is the basis of the equivalent circuit simulation of FIG. is there.
The inductance Lg represents the above-mentioned GND common impedance, and the capacitance Cc represents the capacitive coupling between the input electrode 14T and the output electrode 14R. here,
The common impedance between GNDs is represented by the common inductance Lg between GNDs under the practical assumption that the resistance value of the terminal 22G, the GND pattern 34G, and the solder or the like connecting them is sufficiently small.

【００１２】検討の第３段階として、発明者は、図３の
等価回路モデルを用いて数値シミュレーションを実行
し、その結果（図４）を図１の実測結果と比較した。更
に、この比較の結果を、図１と図２の比較の結果と、比
較した。その結果、第１に、図３の等価回路モデルのほ
うが従来の等価回路モデルより正確に、実際の特性を模
擬・再現できることが判明した。例えば、阻止帯域のう
ち通過帯域のすぐ上下の帯域（７５０ＭＨｚ以下の帯域
や、９００ＭＨｚ〜１．５ＧＨｚ程度までの帯域）に関
しては、明らかに、図４のほうが図２よりも図１に似て
いる。第２に、図１の実測特性に現れている１．８ＧＨ
ｚのトラップが図２では現れていないのに対し図４では
現れていることや、このトラップがなぜ１．８ＧＨｚに
現れるのかも判明した。As a third stage of the examination, the inventor performed a numerical simulation using the equivalent circuit model of FIG. 3 and compared the result (FIG. 4) with the actual measurement result of FIG. Further, the result of this comparison was compared with the result of the comparison of FIGS. As a result, first, it was found that the equivalent circuit model of FIG. 3 can more accurately simulate and reproduce the actual characteristics than the conventional equivalent circuit model. For example, regarding the band immediately above and below the pass band (the band of 750 MHz or less, or the band of 900 MHz to 1.5 GHz) of the stop band, FIG. 4 is clearly more similar to FIG. 1 than FIG. . Second, 1.8 GH, which appears in the measured characteristics of FIG.
It was also found that the z trap does not appear in FIG. 2 but appears in FIG. 4 and why this trap appears at 1.8 GHz.

【００１３】発明者が明らかにした事項のうちトラップ
が１．８ＧＨｚに現れる理由は、以下の通りである。ま
ず、前述のようにＳＡＷフィルタは圧電性のＳＡＷ基板
１０上に電極１４Ｔ、１４Ｒ及び１４Ｇを被着形成した
構成を有しているから、その通過帯域に比べ十分高い周
波数帯域では、一群の入力電極対１２Ｔ及び一群の出力
電極対１２Ｒがそれぞれ容量Ｃｔｉ又はＣｔｏと等価で
あると見なせる（図５（ａ））。但し、ここでは入力電
極１４Ｔ（又は出力電極１４Ｒ）とＧＮＤ電極１４Ｇと
の容量結合は無視している。高い周波数帯域にて有効な
図５（ａ）の等価回路は、周知の回路変形規則により、
図５（ｂ）の形に変形できる。図５（ｂ）に現れている
容量Ｃｘ及びＣｙは、それぞれ次の式Among the matters made clear by the inventor, the reason why the trap appears at 1.8 GHz is as follows. First, as described above, the SAW filter has a structure in which the electrodes 14T, 14R, and 14G are formed on the piezoelectric SAW substrate 10 by deposition, so that in a frequency band sufficiently higher than the pass band, a group of input signals is input. It can be considered that the electrode pair 12T and the group of output electrode pairs 12R are equivalent to the capacitance Cti or Cto, respectively (FIG. 5A). However, the capacitive coupling between the input electrode 14T (or the output electrode 14R) and the GND electrode 14G is ignored here. The equivalent circuit of FIG. 5 (a), which is effective in a high frequency band, is
It can be transformed into the shape shown in FIG. Capacitances Cx and Cy appearing in FIG.

【数１】Ｃｘ＝Ｃｔ＋２Ｃｃ Ｃｙ＝Ｃｔ／Ｃｃ・（Ｃｔ＋２Ｃｃ） にて表すことができる。但し、ここでは、計算の便宜の
ためＣｔｉ及びＣｔｏがいずれも等しいと仮定しこれを
Ｃｔと表している。上式にて表される容量のうちＣｙは
Ｌｇと直列共振し、ＳＡＷフィルタの通過特性上でトラ
ップを発生させる。このトラップの周波数Ｆｐは、次の
式[Expression 1] Cx = Ct + 2Cc Cy = Ct / Cc · (Ct + 2Cc) However, here, for convenience of calculation, it is assumed that both Cti and Cto are equal, and this is represented as Ct. Cy of the capacitance expressed by the above equation resonates in series with Lg and causes a trap on the pass characteristic of the SAW filter. The frequency Fp of this trap is

【数２】 Ｆｐ＝１／｛２π（ＬｇＣｙ）1/2 ｝ ＝１／［２π｛ＬｇＣｔ／Ｃｃ・（Ｃｔ＋２Ｃｃ）｝
1/2 ］ にて表すことができる（Ｃｔ＞＞Ｃｃ）。発明者は、他
方で、題材としたＳＡＷフィルタに関しＣｃ及びＬｇを
変化させながら、Ｆｐ＝１．８ＧＨｚが概ね成立するＣ
ｃ及びＬｇを推定し、これらがそれぞれ０．０８ｐＦ、
０．０５ｎＨであるというデータを得た。その際、Ｃｔ
としては３．２ｐＦの値を用いた。このＣｔ，Ｃｃ及び
Ｌｇを上のＦｐの式に代入すると、Ｆｐ＝１．９４ＧＨ
ｚが得られる。## EQU00002 ## Fp = 1 / {2.pi. (LgCy) 1/2 } = 1 / [2.pi. {LgCt / Cc. (Ct + 2Cc)}
1/2 ] can be represented (Ct >> Cc). On the other hand, the inventor, while changing Cc and Lg with respect to the SAW filter used as the subject, Cp at which Fp = 1.8 GHz is substantially established.
c and Lg are estimated to be 0.08 pF and
The data obtained was 0.05 nH. At that time, Ct
The value used was 3.2 pF. Substituting Ct, Cc, and Lg into the above Fp formula, Fp = 1.94GH
z is obtained.

【００１４】このように、発明者による検討により、電
極対の等価容量を示すＣｔや入出力間二次結合を示すＣ
ｃ及びＬｇが既知であればトラップの周波数Ｆｐを予測
できることが明らかになった。これは、逆にいえば、Ｃ
ｃやＬｇを適宜調整することができれば、図１の特性上
１．８ＧＨｚ近傍に現れているトラップを他の帯域例え
ば通過帯域のすぐ上側に移動させられること、ひいては
通過帯域のすぐ上側における阻止帯域減衰量を増大させ
ることができることを、表している。Thus, according to the study by the inventor, Ct indicating the equivalent capacitance of the electrode pair and C indicating the secondary coupling between the input and output.
It was revealed that the trap frequency Fp can be predicted if c and Lg are known. Conversely, this is C
If c and Lg can be adjusted appropriately, the trap appearing in the vicinity of 1.8 GHz on the characteristic of FIG. 1 can be moved to another band, for example, just above the pass band, and by extension, the stop band just above the pass band. This means that the amount of attenuation can be increased.

【００１５】本発明の第１の特徴は、図６中実線で示さ
れているように従来のＬｇに意図的な増減Ｌｇを付し及
び／又は同図中破線で示されているように従来のＣｃに
意図的な増減ΔＣｃを付す手段を提供することにより、
トラップの周波数Ｆｐを任意の周波数に移動可能にする
ことである。かかる手段例えばＬｇの増大手段の提供に
より、従来例えば１．８ＧＨｚに現れていたトラップを
例えば８００ＭＨｚ帯にある通過帯域の近傍まで移動さ
せることが可能になり、従って通過帯域近傍における阻
止域減衰量を増大させることができる。The first feature of the present invention is to add an intentional increase / decrease Lg to the conventional Lg as shown by the solid line in FIG. 6 and / or as shown by the broken line in FIG. By providing a means for intentionally increasing or decreasing ΔCc to Cc of
This is to make the frequency Fp of the trap movable to any frequency. By providing such a means, for example, a means for increasing Lg, it becomes possible to move the trap that has conventionally appeared at 1.8 GHz, for example, to the vicinity of the pass band in the 800 MHz band, so that the stop band attenuation amount near the pass band can be reduced. Can be increased.

【００１６】本発明の第２の特徴は、増減ΔＬｇ又はΔ
Ｃｃを提供する手段として実装先の回路基板の導電パタ
ーンやスルーホールを利用しているため、ＳＡＷフィル
タ自体の構成の変更、部品の追加、大規模な設計変更等
を伴うことがなく、安価かつ簡便に実施できることであ
る。即ち、本発明で利用している入出力間二次結合Ｌｇ
及びＣｃは、ＳＡＷフィルタの製造乃至実装に際しては
ほぼ必須的に生じ、これまで要求特性の実現の支障とし
てとらえられてきた現象であるから、これを増減調整す
る本発明の構成は、本質的に、比較的小規模な変形のみ
で実施できる。また、ＳＡＷフィルタユーザ（例えば通
信機器セット等の設計者）から見れば、設計発注時にＳ
ＡＷフィルタ設計者に対し要求した特性と若干異なる特
性を実現しようとするときに、改めてＳＡＷフィルタ設
計者に対し発注し直す又は要求特性に係る仕様を訂正す
る必要がなくなり、従ってより安価かつ迅速に作業を進
めることが可能になる。更に、上述のように入出力間二
次結合を逆用する本発明においては、要求特性を満たす
ことができる範囲内であれば、ＳＡＷフィルタ実装面を
回路基板のＧＮＤ面及び部品実装面のいずれとしてもよ
くなる。即ち、従来は“Ｌｇをできるだけ小さくする”
ことが求められていたのに対し本発明の実施に際しては
例えば“Ｌｇを必要な値まで大きくする”ことが求めら
れるのであるから、ＳＡＷフィルタの実装面を、Ｌｇを
比較的小さくできるＧＮＤ面に限定する必要がなくな
る。The second feature of the present invention is to increase / decrease ΔLg or Δ
Since the conductive pattern and the through holes of the circuit board of the mounting destination are used as a means for providing Cc, there is no need to change the configuration of the SAW filter itself, addition of parts, large-scale design change, etc. It can be carried out easily. That is, the secondary coupling Lg between input and output used in the present invention
Since C and Cc are phenomena that are almost inevitable when manufacturing or mounting a SAW filter, and have been regarded as obstacles to the realization of required characteristics, the configuration of the present invention for increasing or decreasing them is essentially the same. , Can be implemented with only a relatively small modification. From the viewpoint of SAW filter users (for example, designers of communication equipment sets, etc.), S
When trying to realize a characteristic that is slightly different from the characteristic required by the AW filter designer, it is not necessary to reorder the SAW filter designer or correct the specification relating to the required characteristic, and therefore, it is cheaper and faster. It becomes possible to proceed with the work. Further, in the present invention in which the secondary coupling between the input and output is reversely used as described above, the SAW filter mounting surface is either the GND surface of the circuit board or the component mounting surface as long as the required characteristics can be satisfied. Will be better as well. That is, conventionally, "Lg is made as small as possible"
In contrast to the above, it is required to "increase Lg to a required value" in the practice of the present invention. Therefore, the mounting surface of the SAW filter should be a GND surface capable of making Lg relatively small. There is no need to limit it.

【００１７】これらの特徴は、より具体的には、次のよ
うな構成を有する基板実装方法にて実現できる。まず、
本発明の第１の構成においては、入力電極、出力電極及
びＧＮＤ電極がその表面に形成されたＳＡＷ基板と、そ
の内部に上記ＳＡＷ基板を収納しかつその一の外表面に
各々上記入力電極、出力電極又はＧＮＤ電極と導電接続
された入力端子、出力端子及びＧＮＤ端子が設けられた
パッケージとを備えるＳＡＷフィルタを、回路基板上に
実装するに際し、上記回路基板の一方の面に少なくとも
ＧＮＤランドを、他方の面にＧＮＤパターンをそれぞれ
設けておき、その後、上記ＧＮＤランドに上記ＧＮＤ端
子が導電接続されるよう上記ＳＡＷフィルタを上記一方
の面に実装し、上記ＧＮＤ電極と上記ＧＮＤパターンと
の間に生じる二次的かつ寄生的なインダクタンスＬｇの
値が目標値となるよう、予めその個数、形状、寸法又は
位置を設定したスルーホールを介し、かつ上記実装に前
後して、上記ＧＮＤランドを上記ＧＮＤパターンに導電
接続する。More specifically, these features can be realized by a board mounting method having the following configuration. First,
In the first configuration of the present invention, an SAW substrate having an input electrode, an output electrode and a GND electrode formed on its surface, the SAW substrate housed inside the SAW substrate and each of the input electrodes on one outer surface thereof, When mounting a SAW filter including an input terminal conductively connected to an output electrode or a GND electrode, an output terminal and a package provided with a GND terminal on a circuit board, at least a GND land is provided on one surface of the circuit board. , A GND pattern is provided on the other surface respectively, and then the SAW filter is mounted on the one surface so that the GND terminal is conductively connected to the GND land, and between the GND electrode and the GND pattern. The number, shape, size, or position of the secondary and parasitic inductance Lg generated in the above is set in advance so that the target value is obtained. Via Horu, and back and forth to the mount, and electrically connected to the GND land in the GND pattern.

【００１８】本発明の第２の構成においては、入力電
極、出力電極及びＧＮＤ電極がその表面に形成されたＳ
ＡＷ基板と、その内部に上記ＳＡＷ基板を収納しかつそ
の一の外表面に各々上記入力電極、出力電極又はＧＮＤ
電極と導電接続された入力端子、出力端子及びＧＮＤ端
子が設けられたパッケージとを備えるＳＡＷフィルタ
を、回路基板上に実装するに際し、上記回路基板の一方
の面に少なくともＧＮＤランド、ＧＮＤ導体及びこれら
を導電接続するＧＮＤ導体を予め設けておき、かつ、こ
れらＧＮＤランド、ＧＮＤ導体及びＧＮＤ導体のうちい
ずれかの形状又は寸法を、下記実装後に上記ＧＮＤ電極
と上記ＧＮＤ導体との間に生じる二次的かつ寄生的なイ
ンダクタンスＬｇの値が目標値となるよう設定してお
き、その後、上記ＧＮＤランドに上記ＧＮＤ端子が導電
接続されるよう上記ＳＡＷフィルタを上記一方の面に実
装する。In the second structure of the present invention, an S electrode having an input electrode, an output electrode and a GND electrode formed on the surface thereof.
An AW substrate, and the SAW substrate housed inside the AW substrate, and the input electrode, the output electrode, or the GND on one outer surface thereof.
When mounting a SAW filter having an input terminal conductively connected to an electrode, a package provided with an output terminal and a GND terminal on a circuit board, at least a GND land, a GND conductor and these on one surface of the circuit board. Is previously provided with a GND conductor for conductively connecting, and any shape or size of these GND land, GND conductor, and GND conductor is formed between the GND electrode and the GND conductor after the following mounting. The value of the static and parasitic inductance Lg is set to a target value, and then the SAW filter is mounted on the one surface so that the GND terminal is conductively connected to the GND land.

【００１９】そして、本発明の第３の構成においては、
入力電極、出力電極及びＧＮＤ電極がその表面に形成さ
れたＳＡＷ基板と、その内部に上記ＳＡＷ基板を収納し
かつその一の外表面に各々上記入力電極、出力電極又は
ＧＮＤ電極と導電接続された入力端子、出力端子及びＧ
ＮＤ端子が設けられたパッケージとを備えるＳＡＷフィ
ルタを、回路基板上に実装するに際し、上記回路基板の
一方の面に少なくとも入力ランド及び出力ランドを予め
設けておき、かつ、これら入力ランド及び出力ランドの
形状、寸法又は間隔を、下記実装後に上記入力電極と上
記出力電極との間に生じる二次的かつ寄生的な容量Ｃｃ
の値が目標値となるよう設定しておき、その後、上記入
力ランド及び出力ランドに上記入力端子及び出力端子の
うちが対応するものが導電接続されるよう上記ＳＡＷフ
ィルタを上記一方の面に実装する。In the third structure of the present invention,
An SAW substrate having an input electrode, an output electrode and a GND electrode formed on its surface, and the SAW substrate housed inside the SAW substrate and conductively connected to the input electrode, the output electrode or the GND electrode on one outer surface thereof. Input terminal, output terminal and G
When mounting a SAW filter including a package provided with an ND terminal on a circuit board, at least an input land and an output land are previously provided on one surface of the circuit board, and the input land and the output land are provided. The shape, size, or spacing of Cc is determined by the secondary and parasitic capacitance Cc generated between the input electrode and the output electrode after the following mounting.
Is set to the target value, and then the SAW filter is mounted on the one surface so that the input land and the output land corresponding to the input terminal and the output terminal are conductively connected. To do.

【００２０】これらの構成の作用効果に関しては、既に
述べた本発明の原理及びその特徴事項に関する説明か
ら、当業者にとり一意に解釈できかつ自明である。更
に、本発明は、基板実装方法という表現形式にて限定さ
れるべきものではなく、例えば、「ＳＡＷフィルタを実
装するのに適する回路基板の構造」「ＳＡＷフィルタの
特性調整方法」等として表現することもできる。この種
の表現形式の変更に関しても、これまでの説明から、当
業者にとり一意に解釈できかつ自明である。The operation and effect of these configurations can be uniquely interpreted and obvious to those skilled in the art from the above description of the principle of the present invention and its characteristic features. Furthermore, the present invention should not be limited to the expression form of a board mounting method, and is expressed as, for example, “structure of circuit board suitable for mounting SAW filter”, “SAW filter characteristic adjusting method”, and the like. You can also The change in the expression format of this kind can be uniquely interpreted and obvious to those skilled in the art from the above description.

【００２１】[0021]

【発明の実施の形態】以下、本発明の好適な実施形態に
関して図面に基づき説明する。なお、図１１〜１３に示
す従来技術と同一の又は対応する構成については同一の
符号を付し、説明を省略する。また、図１〜図６を用い
た本発明の原理説明に使用した符号を、実施形態の説明
においても引き続き使用する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. It should be noted that the same or corresponding configurations as those of the conventional technique shown in FIGS. Further, the reference numerals used for explaining the principle of the present invention using FIGS. 1 to 6 will be continuously used in the description of the embodiments.

【００２２】図７に、本発明の第１実施形態に係る基板
実装方法が示されている。この実施形態においては、回
路基板３０の図中上側の面に、入力ランド３２Ｔ、出力
ランド３２Ｒ及びＧＮＤランド３２Ｇが被着形成されて
いる。これらのランド３２Ｔ、３２Ｒ及び３２Ｇは、実
装すべきＳＡＷフィルタの端子２２Ｔ、２２Ｒ及び２２
Ｇに対応して設けられており、このＳＡＷフィルタを回
路基板３０上に実装する際には、これらの端子２２Ｔ、
２２Ｒ及び２２Ｇをランド３２Ｔ、３２Ｒ及び３２Ｇの
うち対応するものと半田等により導電接続できるよう、
ＳＡＷフィルタを回路基板３０に対し位置決めし、その
後半田付等を行う。FIG. 7 shows a board mounting method according to the first embodiment of the present invention. In this embodiment, an input land 32T, an output land 32R, and a GND land 32G are adhered to the upper surface of the circuit board 30 in the drawing. These lands 32T, 32R and 32G are the terminals 22T, 22R and 22 of the SAW filter to be mounted.
It is provided corresponding to G, and when the SAW filter is mounted on the circuit board 30, these terminals 22T,
22R and 22G can be conductively connected to the corresponding one of the lands 32T, 32R and 32G by soldering or the like.
The SAW filter is positioned with respect to the circuit board 30, and then soldering or the like is performed.

【００２３】また、図示しないが、回路基板３０の図中
下側の面には、他の回路部品との接続のための導電パタ
ーンが被着形成されており、ランド３２Ｔ、３２Ｒ及び
３２Ｇはいずれもスルーホール３８を介して裏側の対応
する導電パターンに導電接続される。また、本実施形態
においては、特にＧＮＤランド３２Ｇにかかるスルーホ
ール３８の個数が、実現すべきＬｇの値に応じて、設定
されている。このように、本実施形態においては、スル
ーホール３８の個数の設定によって任意のＬｇを実現可
能とし、通過帯域近傍における阻止帯域減衰量の改善
等、特性改善の効果を達成している。Although not shown, a conductive pattern for connection with other circuit components is formed on the lower surface of the circuit board 30 in the figure, and the lands 32T, 32R and 32G are all formed. Is also conductively connected to the corresponding conductive pattern on the back side through the through hole 38. In addition, in the present embodiment, the number of the through holes 38 that are particularly related to the GND land 32G is set according to the value of Lg to be realized. As described above, in this embodiment, an arbitrary Lg can be realized by setting the number of through holes 38, and the effect of characteristic improvement such as improvement of the stopband attenuation near the passband is achieved.

【００２４】この効果をより具体的に説明するため、発
明の原理説明において題材としたＳＡＷフィルタ、すな
わち８００ＭＨｚ帯を通過帯域とするＳＡＷフィルタを
考える。前述の従来技術においては、Ｌｇの値をできる
だけ小さくすることを前提として基板実装が行われてい
たため、Ｌｇは０．０５ｎＨという小さな値になってお
り、そのため１．８ＧＨｚにトラップが現れていた（図
１参照）。これに対して本実施形態の構成を使用しＬｇ
を例えば０．２ｎＨにすることにより、トラップの周波
数を１．８ＧＨｚからより低い周波数例えば通過帯域の
すぐ上側の周波数まで低めることができる。本発明の発
明者は、本実施形態においてＬｇ＝０．２ｎＨとなるよ
うＧＮＤランド３２Ｇに係るスルーホール３８の個数を
設定した例に関し、その通過特性の実測を行なった（図
８）。この図からも明らかなように、本実施形態におい
ては、図１に示す従来技術のそれに比べ、特に通過帯域
近傍の阻止域減衰量という限られた範囲ではあるが、特
性の改善が現れている。In order to explain this effect more specifically, let us consider the SAW filter used as the subject of the explanation of the principle of the invention, that is, the SAW filter having a pass band in the 800 MHz band. In the above-mentioned conventional technique, since the substrate was mounted on the premise that the value of Lg was made as small as possible, the value of Lg was as small as 0.05 nH, and therefore a trap appeared at 1.8 GHz ( (See FIG. 1). On the other hand, using the configuration of the present embodiment, Lg
By, for example, 0.2 nH, the trap frequency can be lowered from 1.8 GHz to a lower frequency, for example, just above the pass band. The inventor of the present invention measured the pass characteristics of the example in which the number of the through holes 38 related to the GND land 32G was set so that Lg = 0.2 nH in the present embodiment (FIG. 8). As is clear from this figure, in the present embodiment, compared to that of the conventional technique shown in FIG. 1, the characteristic is improved, although it is in a limited range of the stop band attenuation amount particularly near the pass band. .

【００２５】なお、図７にはＧＮＤランド３２Ｇにかか
るスルーホール３８の個数を実現すべきＬｇの値に応じ
て設定する例のみを示したが、ＧＮＤランド３２Ｇにか
かるスルーホール３８の形状、寸法、位置等を目標とす
べきＬｇの値に応じて設定ないし調整する構成によって
も、同様の作用効果を実現することができる。Although FIG. 7 shows only an example in which the number of through holes 38 in the GND land 32G is set according to the value of Lg to be realized, the shape and size of the through hole 38 in the GND land 32G are shown. A similar effect can be achieved by a configuration in which the position, etc. are set or adjusted according to the target Lg value.

【００２６】図９に、本発明の第２実施形態に係る基板
実装方法を示す。この実施形態においては、回路基板３
０の図中上側の面に入力ランド３２Ｔ、出力ランド３２
Ｒ及びＧＮＤランド３２Ｇが、前述の第１実施形態と同
様被着形成されている。また、回路基板３０の図中下側
の面には、図示しないが、入力ランド３２Ｔ及び出力ラ
ンド３２Ｒとスルーホール３８を介し導電接続される導
電パターンが被着形成されている。本実施形態が前述の
第１実施形態と相違しているのは、ＧＮＤランド３２Ｇ
の形成面と同一の面にＧＮＤ導体４０を設け、ＧＮＤラ
ンド３２ＧとＧＮＤ導体４０との間をやはり同じ面に被
着形成されているストリップライン４２にて導電接続し
ている点である。なお、図中、２個設けられているＧＮ
Ｄランド３２Ｇのうち一方のみをＧＮＤ導体４０に導電
接続しているが、これは、端子２２Ｇがパッケージ２０
内において互いに導電接続されているため一方のみでよ
いことによる（従来技術の欄を参照）。FIG. 9 shows a board mounting method according to the second embodiment of the present invention. In this embodiment, the circuit board 3
The input land 32T and the output land 32 are provided on the upper surface in FIG.
The R and GND lands 32G are adhered and formed as in the first embodiment described above. Although not shown, a conductive pattern that is conductively connected to the input land 32T and the output land 32R through the through hole 38 is formed on the lower surface of the circuit board 30 in the drawing. This embodiment differs from the first embodiment described above in that the GND land 32G is used.
That is, the GND conductor 40 is provided on the same surface as the surface on which is formed, and the GND land 32G and the GND conductor 40 are conductively connected by the strip line 42 that is also formed on the same surface. In the figure, two GNs are provided.
Only one of the D lands 32G is conductively connected to the GND conductor 40. This is because the terminal 22G is connected to the package 20.
This is because only one of them is necessary because they are electrically conductively connected to each other (see the section of the prior art).

【００２７】本実施形態においても、特にストリップラ
イン４２においてインダクタンスが発生するため、この
インダクタンスを以て、Ｌｇに増減ΔＬｇを復すること
ができる。従って、この実施形態においても、前述の第
１実施形態と同様の作用効果が得られる。なお、厳密に
は、インダクタンスはストリップライン４２のみならず
ＧＮＤ導体４０及びＧＮＤランド３２Ｇにおいても発生
するから、ＧＮＤランド３２Ｇ、ストリップライン４２
及びＧＮＤ導体４０のいずれの形状、寸法等を調整する
ことによっても、同様の作用効果を達成できる。Also in the present embodiment, an inductance is generated especially in the strip line 42, so that the increase / decrease ΔLg can be restored to Lg by this inductance. Therefore, also in this embodiment, the same effect as that of the above-described first embodiment can be obtained. Strictly speaking, the inductance is generated not only in the strip line 42 but also in the GND conductor 40 and the GND land 32G, so that the GND land 32G and the strip line 42 are formed.
The same effect can be achieved by adjusting any of the shapes and dimensions of the GND conductor 40 and the GND conductor 40.

【００２８】図１０に、本発明の第３実施形態に係る基
板実装方法を示す。この実施形態においては、おおむ
ね、前述の従来技術と同様の基板構造が採用されてい
る。但し、この実施形態においては、入力ランド３２Ｔ
にかかるギャップ３６Ｔと出力ランド３２Ｒにかかるギ
ャップ３６Ｒとが分離しておらず、一体のギャップ３６
を構成している。従って、入力ランド３２Ｔと出力ラン
ド３２Ｒの間はＧＮＤパターン３４Ｇによって遮蔽され
ておらず、両者の間には容量性の結合が発生する。この
容量性の結合は前述のＣｃの増減ΔＣｃとして寄与す
る。この構成によれば、ギャップ３６の形状、寸法、或
いは入力ランド３２Ｔ又は出力ランド３２Ｒの形状、寸
法、間隔等を調整することにより、Ｃｃを適宜目標値に
設定ないし調整することができ、ひいては高周波域にあ
るトラップを通過帯域近傍に移すといった特性調整がや
はり可能である。FIG. 10 shows a board mounting method according to the third embodiment of the present invention. In this embodiment, a substrate structure similar to that of the above-mentioned conventional technique is adopted. However, in this embodiment, the input land 32T
Is not separated from the gap 36T applied to the output land 32R and the gap 36R applied to the output land 32R.
Is composed. Therefore, the input land 32T and the output land 32R are not shielded by the GND pattern 34G, and a capacitive coupling occurs between them. This capacitive coupling contributes to the increase / decrease ΔCc of Cc described above. According to this configuration, by adjusting the shape and size of the gap 36 or the shape, size, and spacing of the input land 32T or the output land 32R, Cc can be set or adjusted to a target value as appropriate, and by extension, high frequency can be achieved. It is also possible to adjust the characteristics by moving traps in the region to near the pass band.

【００２９】以上の各実施形態では、概ね、図１１に示
すように入力電極対１２ＴのＧＮＤ電極１４と出力電極
対１２ＲのＧＮＤ電極１４ＧとをＳＡＷ基板１０上で接
続する構成を、前提としていた。しかし、この接続を、
ＳＡＷ基板１０上の導体１６Ｇではなく、パッケージ２
０内部又は表面の配線又はパターン導体や、回路基板３
０上の配線又はパターンで、実現してもかまわない。In each of the above-described embodiments, it is generally assumed that the GND electrode 14 of the input electrode pair 12T and the GND electrode 14G of the output electrode pair 12R are connected on the SAW substrate 10 as shown in FIG. . But this connection
Instead of the conductor 16G on the SAW substrate 10, the package 2
0 Internal or surface wiring or pattern conductor, circuit board 3
It may be realized by wiring or pattern on 0.

【図面の簡単な説明】[Brief description of drawings]

【図１】 従来のＳＡＷフィルタ（基板実装後）の実測
通過特性を示す図である。FIG. 1 is a diagram showing measured pass characteristics of a conventional SAW filter (after mounting on a board).

【図２】 従来の等価回路モデルに基づく通過特性の数
値シミュレーション結果を示す図である。FIG. 2 is a diagram showing a result of numerical simulation of pass characteristics based on a conventional equivalent circuit model.

【図３】 入出力間２次結合を考慮した等価回路モデル
を示す回路図である。FIG. 3 is a circuit diagram showing an equivalent circuit model considering a secondary coupling between input and output.

【図４】 図３の等価回路モデルに基づく通過特性の数
値シミュレーションの結果を示す図である。4 is a diagram showing a result of a numerical simulation of a pass characteristic based on the equivalent circuit model of FIG.

【図５】 図３に示す等価回路モデルの変形を示す図で
あり、特に（ａ）は通過帯域に比べ十分高い周波数帯域
における等価回路を、（ｂ）はこれを変形した等価回路
を、それぞれ示す図である。5A and 5B are diagrams showing a modification of the equivalent circuit model shown in FIG. 3, in which FIG. 5A is an equivalent circuit in a frequency band sufficiently higher than the pass band, and FIG. 5B is a modified equivalent circuit thereof. FIG.

【図６】 本発明の基本原理を示す等価回路図である。FIG. 6 is an equivalent circuit diagram showing the basic principle of the present invention.

【図７】 本発明の第１実施形態に係る基板実装方法を
示す分解斜視図である。FIG. 7 is an exploded perspective view showing the board mounting method according to the first embodiment of the present invention.

【図８】 この実施形態における通過特性の測定結果を
示す図である。FIG. 8 is a diagram showing measurement results of pass characteristics in this embodiment.

【図９】 本発明の第２実施形態に係る基板実装方法を
示す分解斜視図である。FIG. 9 is an exploded perspective view showing a board mounting method according to a second embodiment of the present invention.

【図１０】 本発明の第３実施形態に係る基板実装方法
を示す分解斜視図である。FIG. 10 is an exploded perspective view showing a board mounting method according to a third embodiment of the present invention.

【図１１】 多電極型ＳＡＷフィルタにおける電極配置
の一例を示す概略平面図である。FIG. 11 is a schematic plan view showing an example of electrode arrangement in a multi-electrode SAW filter.

【図１２】 表面実装型パッケージの一例構成を示す斜
視図である。FIG. 12 is a perspective view showing an example configuration of a surface mount package.

【図１３】 一従来技術に係る基板実装方法を示す分解
斜視図である。FIG. 13 is an exploded perspective view showing a board mounting method according to a conventional technique.

【符号の説明】[Explanation of symbols]

１２Ｔ 入力電極対、１２Ｒ 出力電極対、１４Ｔ 入
力電極、１４Ｒ 出力電極、１４Ｇ ＧＮＤ電極、２０
パッケージ、２２Ｔ 入力端子、２２Ｒ 出力端子、
２２Ｇ ＧＮＤ端子、３０ 回路基板、３２Ｔ 入力ラ
ンド、３２Ｒ出力ランド、３２Ｇ ＧＮＤランド、３４
Ｇ ＧＮＤパターン、３６ ギャップ、３８ スルーホ
ール、４０ ＧＮＤ導体、４２ ストリップライン、Ｌ
ｇ ＧＮＤ間共通インダクタンス、Ｃｃ 入出力間結合
容量、ΔＬｇ Ｌｇの増減分、ΔＣｃ Ｃｃの増減分。12T input electrode pair, 12R output electrode pair, 14T input electrode, 14R output electrode, 14G GND electrode, 20
Package, 22T input terminal, 22R output terminal,
22G GND terminal, 30 circuit board, 32T input land, 32R output land, 32G GND land, 34
G GND pattern, 36 gap, 38 through hole, 40 GND conductor, 42 strip line, L
g GND common inductance, Cc input-output coupling capacitance, ΔLg Lg increase / decrease, ΔCc Cc increase / decrease.

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 入力電極、出力電極及びＧＮＤ電極がそ
の表面に形成されたＳＡＷ基板と、その内部に上記ＳＡ
Ｗ基板を収納しかつその一の外表面に各々上記入力電
極、出力電極又はＧＮＤ電極と導電接続された入力端
子、出力端子及びＧＮＤ端子が設けられたパッケージと
を備えるＳＡＷフィルタを、回路基板上に実装するに際
し、 上記回路基板の一方の面に少なくともＧＮＤランドを、
他方の面にＧＮＤパターンをそれぞれ設けておき、 その後、上記ＧＮＤランドに上記ＧＮＤ端子が導電接続
されるよう上記ＳＡＷフィルタを上記一方の面に実装
し、 上記ＧＮＤ電極と上記ＧＮＤパターンとの間に生じる二
次的かつ寄生的なインダクタンスの値が目標値となるよ
う、予めその個数、形状、寸法又は位置を設定したスル
ーホールを介し、かつ上記実装に前後して、上記ＧＮＤ
ランドを上記ＧＮＤパターンに導電接続することを特徴
とする基板実装方法。1. A SAW substrate having an input electrode, an output electrode and a GND electrode formed on the surface thereof, and the SA inside the SAW substrate.
A SAW filter including a W substrate and a package provided with an input terminal, an output terminal and a GND terminal which are conductively connected to the input electrode, the output electrode or the GND electrode on one outer surface of the SAW filter is provided on a circuit board. When mounting on, at least the GND land on one surface of the circuit board,
A GND pattern is provided on each of the other surfaces, and then the SAW filter is mounted on the one surface so that the GND terminal is conductively connected to the GND land, and the GND pattern is provided between the GND electrode and the GND pattern. The above-mentioned GND is provided through through-holes whose numbers, shapes, dimensions, or positions are set in advance so that the value of the generated secondary and parasitic inductance becomes a target value, and before and after the mounting.
A method of mounting a substrate, characterized in that a land is conductively connected to the GND pattern. 【請求項２】 入力電極、出力電極及びＧＮＤ電極がそ
の表面に形成されたＳＡＷ基板と、その内部に上記ＳＡ
Ｗ基板を収納しかつその一の外表面に各々上記入力電
極、出力電極又はＧＮＤ電極と導電接続された入力端
子、出力端子及びＧＮＤ端子が設けられたパッケージと
を備えるＳＡＷフィルタを、回路基板上に実装するに際
し、 上記回路基板の一方の面に少なくともＧＮＤランド、Ｇ
ＮＤ導体及びこれらを導電接続するＧＮＤ導体を予め設
けておき、かつ、これらＧＮＤランド、ＧＮＤ導体及び
ＧＮＤ導体のうちいずれかの形状又は寸法を、下記実装
後に上記ＧＮＤ電極と上記ＧＮＤ導体との間に生じる二
次的かつ寄生的なインダクタンスの値が目標値となるよ
う設定しておき、 その後、上記ＧＮＤランドに上記ＧＮＤ端子が導電接続
されるよう上記ＳＡＷフィルタを上記一方の面に実装す
ることを特徴とする基板実装方法。2. A SAW substrate having an input electrode, an output electrode and a GND electrode formed on the surface thereof, and the SA inside the SAW substrate.
A SAW filter including a W substrate and a package provided with an input terminal, an output terminal and a GND terminal which are conductively connected to the input electrode, the output electrode or the GND electrode on one outer surface of the SAW filter is provided on a circuit board. When mounting on the one side of the circuit board, at least the GND land, G
An ND conductor and a GND conductor for conductively connecting them are provided in advance, and any one of these GND land, GND conductor, and GND conductor is formed between the GND electrode and the GND conductor after the following mounting. The value of the secondary and parasitic inductance generated in 1) is set to a target value, and then the SAW filter is mounted on the one surface so that the GND terminal is conductively connected to the GND land. A board mounting method characterized by the above. 【請求項３】 入力電極、出力電極及びＧＮＤ電極がそ
の表面に形成されたＳＡＷ基板と、その内部に上記ＳＡ
Ｗ基板を収納しかつその一の外表面に各々上記入力電
極、出力電極又はＧＮＤ電極と導電接続された入力端
子、出力端子及びＧＮＤ端子が設けられたパッケージと
を備えるＳＡＷフィルタを、回路基板上に実装するに際
し、 上記回路基板の一方の面に少なくとも入力ランド及び出
力ランドを予め設けておき、かつ、これら入力ランド及
び出力ランドの形状、寸法又は間隔を、下記実装後に上
記入力電極と上記出力電極との間に生じる二次的かつ寄
生的な容量の値が目標値となるよう設定しておき、 その後、上記入力ランド及び出力ランドに上記入力端子
及び出力端子のうちが対応するものが導電接続されるよ
う上記ＳＡＷフィルタを上記一方の面に実装することを
特徴とする基板実装方法。3. A SAW substrate having an input electrode, an output electrode, and a GND electrode formed on the surface thereof, and the SA inside the SAW substrate.
A SAW filter including a W substrate and a package provided with an input terminal, an output terminal and a GND terminal which are conductively connected to the input electrode, the output electrode or the GND electrode on one outer surface of the SAW filter is provided on a circuit board. At the time of mounting on the above-mentioned circuit board, at least an input land and an output land are provided in advance on the one surface of the circuit board, and the shape, size, or interval of the input land and the output land are set to the input electrode and the output after mounting The value of the secondary and parasitic capacitance generated between the electrodes is set to the target value.After that, the one whose input terminal and output terminal corresponds to the above input land and output land is conductive. A substrate mounting method comprising mounting the SAW filter on the one surface so as to be connected.
JP13699396A 1996-05-30 1996-05-30 Substrate mounting method of SAW filter Expired - Lifetime JP3895397B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13699396A JP3895397B2 (en) 1996-05-30 1996-05-30 Substrate mounting method of SAW filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13699396A JP3895397B2 (en) 1996-05-30 1996-05-30 Substrate mounting method of SAW filter

Publications (2)

Publication Number Publication Date
JPH09321569A true JPH09321569A (en) 1997-12-12
JP3895397B2 JP3895397B2 (en) 2007-03-22

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JP2002141771A (en) * 2000-08-21 2002-05-17 Murata Mfg Co Ltd Surface acoustic wave filter
KR20050060382A (en) * 2003-12-16 2005-06-22 엘지이노텍 주식회사 Surface acoustic wave filter
US7154359B2 (en) * 2003-05-20 2006-12-26 Fujitsu Media Devices Limited Surface acoustic wave filter and duplexer including the same
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JP2002141771A (en) * 2000-08-21 2002-05-17 Murata Mfg Co Ltd Surface acoustic wave filter
US6919777B2 (en) 2000-08-21 2005-07-19 Murata Manufacturing Co., Ltd. Surface acoustic wave filter device
US7154359B2 (en) * 2003-05-20 2006-12-26 Fujitsu Media Devices Limited Surface acoustic wave filter and duplexer including the same
EP1482639A3 (en) * 2003-05-20 2007-02-28 Fujitsu Media Devices Limited Surface acoustic wave filters and duplexers including the same
KR100860211B1 (en) * 2003-05-20 2008-09-24 후지쓰 메디아 데바이스 가부시키가이샤 Surface acoustic wave filter and duplexer including the same
KR20050060382A (en) * 2003-12-16 2005-06-22 엘지이노텍 주식회사 Surface acoustic wave filter
WO2010052969A1 (en) * 2008-11-04 2010-05-14 株式会社村田製作所 Elastic wave filter device and module comprising the elastic wave filter device
JP5056952B2 (en) * 2008-11-04 2012-10-24 株式会社村田製作所 Elastic wave filter device and module including the same
US8319585B2 (en) 2008-11-04 2012-11-27 Murata Manufacturing Co., Ltd. Elastic wave filter device and module including the same

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