JP4557691B2 - Surface acoustic wave device - Google Patents

Surface acoustic wave device Download PDF

Info

Publication number
JP4557691B2
JP4557691B2 JP2004343097A JP2004343097A JP4557691B2 JP 4557691 B2 JP4557691 B2 JP 4557691B2 JP 2004343097 A JP2004343097 A JP 2004343097A JP 2004343097 A JP2004343097 A JP 2004343097A JP 4557691 B2 JP4557691 B2 JP 4557691B2
Authority
JP
Japan
Prior art keywords
surface acoustic
acoustic wave
pair
electrodes
wave device
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.)
Expired - Fee Related
Application number
JP2004343097A
Other languages
Japanese (ja)
Other versions
JP2006157307A (en
Inventor
大輔 山本
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.)
Kyocera Corp
Original Assignee
Kyocera Corp
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 Kyocera Corp filed Critical Kyocera Corp
Priority to JP2004343097A priority Critical patent/JP4557691B2/en
Publication of JP2006157307A publication Critical patent/JP2006157307A/en
Application granted granted Critical
Publication of JP4557691B2 publication Critical patent/JP4557691B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

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

Description

本発明は、例えば携帯電話等の移動体通信機器や車載用機器、医療用機器等に用いられる弾性表面波装置に関するものである。   The present invention relates to a surface acoustic wave device used for mobile communication devices such as mobile phones, in-vehicle devices, medical devices, and the like.

弾性表面波共振器や弾性表面波フィルタ等の弾性表面波装置には様々な形態が存在するが、圧電基板上に弾性表面波の伝搬方向に沿って一対の反射器を形成し、その反射器の間にＩＤＴ（インターデジタルトランスデューサ）を形成したものが多用されている。このタイプの弾性表面波装置においては、ＩＤＴによって励振された弾性表面波を、その両側に配置された反射器の間で多重反射させて閉じ込めることができるため、Ｑの高い弾性表面波共振器や低損失の弾性表面波フィルタが構成できる。
特開２００２−７６８１８号公報 There are various types of surface acoustic wave devices such as surface acoustic wave resonators and surface acoustic wave filters. A pair of reflectors are formed on a piezoelectric substrate along the propagation direction of the surface acoustic wave, and the reflectors A device in which an IDT (interdigital transducer) is formed between the two is often used. In this type of surface acoustic wave device, the surface acoustic wave excited by the IDT can be confined by multiple reflection between the reflectors disposed on both sides thereof. A low-loss surface acoustic wave filter can be constructed.
JP 2002-76818 A

しかしながら、上述した従来の弾性表面波装置においては、ＩＤＴで発生した弾性表面波の一部が回折によって伝搬方向が変化し、弾性表面波装置の外へ漏洩するという問題があった。これによって弾性表面波装置の弾性表面波エネルギーの閉じ込めが完全ではなく、これに起因する弾性表面波共振器のＱの低下や弾性表面波フィルタの挿入損失の低下が存在していた。   However, the conventional surface acoustic wave device described above has a problem that a part of the surface acoustic wave generated by the IDT changes its propagation direction due to diffraction and leaks out of the surface acoustic wave device. As a result, the surface acoustic wave energy is not completely confined by the surface acoustic wave device, and the Q of the surface acoustic wave resonator and the insertion loss of the surface acoustic wave filter are reduced due to this.

本発明は上記欠点に鑑み案出されたものであり、弾性表面波の漏洩を低減した弾性表面波装置を提供することにある。   The present invention has been devised in view of the above-described drawbacks, and it is an object of the present invention to provide a surface acoustic wave device in which leakage of surface acoustic waves is reduced.

本発明の弾性表面波装置の一態様は、圧電基板上に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の電極指の一端をバスバー電極で接続してなる一対の櫛歯状電極を、前記電極指が互いに噛み合うように対向させてなるＩＤＴを形成するとともに、該ＩＤＴの弾性表面波の伝搬方向の両側に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の反射電極の両端を共通電極で接続してなる一対の反射器を形成してなる弾性表面波装置において、前記一対のバスバー電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成したことを特徴とするものである。
 One aspect of the surface acoustic wave device of the present invention is a pair of comb teeth formed by connecting one end of a plurality of electrode fingers arranged at equal intervals along a propagation direction of a surface acoustic wave on a piezoelectric substrate with bus bar electrodes. The electrode electrodes are formed so as to face each other so that the electrode fingers mesh with each other, and are arranged at equal intervals along the surface acoustic wave propagation direction on both sides of the surface acoustic wave propagation direction of the IDT. In the surface acoustic wave device in which a pair of reflectors are formed by connecting both ends of a plurality of reflective electrodes with a common electrode, at least one slit is provided in each of the pair of bus bar electrodes. And formed vertically.

また、本発明の弾性表面波装置の別の態様は、圧電基板上に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の電極指の一端をバスバー電極で接続してなる一対の櫛歯状電極を、前記電極指が互いに噛み合うように対向させてなるＩＤＴを形成するとともに、該ＩＤＴの弾性表面波の伝搬方向の両側に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の反射電極の両端を一対の共通電極で接続してなる一対の反射器を形成してなる弾性表面波装置において、前記一対の共通電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成したことを特徴とするものである。
In another aspect of the surface acoustic wave device of the present invention, a pair of electrode fingers connected at one end to a piezoelectric substrate at equal intervals along the propagation direction of the surface acoustic wave is connected by a bus bar electrode. Are formed so that the electrode fingers face each other so that the electrode fingers mesh with each other, and are formed at equal intervals along the surface acoustic wave propagation direction on both sides of the surface acoustic wave propagation direction of the IDT. in a pair of reflectors formed surface acoustic wave device comprising a formed by connecting a pair of common electrodes to both ends of the plurality of reflective electrodes disposed on each of the pair of common electrodes, at least one slit, It is formed perpendicular to the plurality of electrode fingers.

更に、本発明の弾性表面波装置の更に別の態様は、圧電基板上に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の電極指の一端をバスバー電極で接続してなる一対の櫛歯状電極を、前記電極指が互いに噛み合うように対向させてなるＩＤＴを形成するとともに、該ＩＤＴの弾性表面波の伝搬方向の両側に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の反射電極の両端を一対の共通電極で接続してなる一対の反射器を形成してなる弾性表面波装置において、前記一対のバスバー電極と前記一対の共通電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成したことを特徴とするものである。
Furthermore, another aspect of the surface acoustic wave device of the present invention is formed by connecting one end of a plurality of electrode fingers arranged at equal intervals along the propagation direction of the surface acoustic wave on the piezoelectric substrate with a bus bar electrode. An IDT is formed by making a pair of comb-like electrodes face each other so that the electrode fingers mesh with each other, and equidistant along both sides of the surface acoustic wave propagation direction of the IDT along the surface acoustic wave propagation direction. In the surface acoustic wave device formed with a pair of reflectors formed by connecting both ends of the plurality of reflective electrodes with a pair of common electrodes, each of the pair of bus bar electrodes and the pair of common electrodes, At least one slit is formed perpendicular to the plurality of electrode fingers.

また更に、本発明の弾性表面波装置は、前記スリットの幅が前記電極指の配列ピッチの１／２より小さくされていることを特徴とするものである。   Furthermore, the surface acoustic wave device of the present invention is characterized in that the width of the slit is smaller than ½ of the arrangement pitch of the electrode fingers.

更にまた、本発明の弾性表面波装置は、前記スリットがそれぞれの前記バスバー電極及び／又は前記共通電極に複数本形成されており、その配列ピッチが前記電極指の配列ピッチより小さくされていることを特徴とするものである。   Furthermore, in the surface acoustic wave device of the present invention, a plurality of the slits are formed in each of the bus bar electrodes and / or the common electrode, and the arrangement pitch thereof is smaller than the arrangement pitch of the electrode fingers. It is characterized by.

本発明の弾性表面波装置の一態様によれば、 前記一対のバスバー電極のそれぞれに、
少なくとも一本のスリットを、前記複数の電極指と垂直に形成している。よって、回折により進行方向がずれてバスバー電極を通過して漏れていく弾性表面波を、スリットで反射
させて弾性表面波装置内に戻すことが可能となり、弾性表面波エネルギーの閉じ込めに優れた高性能の弾性表面波装置とすることが出来る。
According to one aspect of the surface acoustic wave device of the present invention, each of the pair of bus bar electrodes,
At least one slit is formed perpendicular to the plurality of electrode fingers. Therefore, it is possible to reflect the surface acoustic wave, which travels out of direction due to diffraction and leaks through the bus bar electrode, to be reflected by the slit and returned to the surface acoustic wave device. A surface acoustic wave device with high performance can be obtained.

また、本発明の弾性表面波装置の別の態様によれば、前記一対の共通電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成している。よって、回折により進行方向がずれて共通電極を通過して漏れていく弾性表面波を、スリットで反射させて弾性表面波装置内に戻すことが可能となり、弾性表面波エネルギーの閉じ込めに優れた高性能の弾性表面波装置とすることが出来る。
According to another aspect of the surface acoustic wave device of the invention, at least one slit is formed in each of the pair of common electrodes perpendicular to the plurality of electrode fingers. Therefore, it becomes possible to reflect the surface acoustic wave that is traveling in the direction shifted by diffraction and leaks through the common electrode, and reflects it back to the surface acoustic wave device by the slit, which is excellent in confining the surface acoustic wave energy. A surface acoustic wave device with high performance can be obtained.

更に、本発明の弾性表面波装置の更に別の態様によれば、前記一対のバスバー電極と前記一対の共通電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成している。よって、回折により進行方向がずれてバスバー電極を通過して漏れていく弾性表面波と共通電極を通過して漏れていく弾性表面波の両方を、スリットで反射させて弾性表面波装置内に戻すことが可能となり、弾性表面波エネルギーの閉じ込めに更に優れた更に高性能の弾性表面波装置とすることが出来る。
Furthermore, according to still another aspect of the surface acoustic wave device of the present invention, at least one slit is formed perpendicularly to the plurality of electrode fingers in each of the pair of bus bar electrodes and the pair of common electrodes. ing. Therefore, both the surface acoustic wave leaking through the bus bar electrode due to the deviation of the traveling direction due to diffraction and the surface acoustic wave leaking through the common electrode are reflected by the slit and returned to the surface acoustic wave device. Therefore, it is possible to provide a surface acoustic wave device with higher performance that is more excellent in confining surface acoustic wave energy.

また更に、本発明の弾性表面波装置によれば、前記スリットの幅が前記電極指の配列ピッチの１／２より小さくされている場合には、回折により進行方向がずれて漏れていく弾性表面波の一部において、スリットの両側面で反射した波が同相となり、より効率的にスリットで弾性表面波を反射させることが可能となるため、弾性表面波エネルギーの閉じ込めに更に優れた高性能の弾性表面波装置とすることが出来る。
Furthermore, according to the surface acoustic wave device of the present invention, when the width of the slit is smaller than half the arrangement pitch of the electrode fingers, the surface acoustic going leaks deviated traveling direction by the diffraction In some of the waves, the waves reflected on both sides of the slit are in phase, and the surface acoustic waves can be reflected more efficiently by the slits. A surface acoustic wave device can be obtained.

更にまた、本発明の弾性表面波装置によれば、前記スリットがそれぞれの前記バスバー電極及び／又は前記共通電極に複数本形成されており、その配列ピッチが前記電極指の配列ピッチより小さくされている場合には、回折により進行方向がずれて漏れていく弾性表面波の一部を複数本のスリットによってブラッグ反射させることができ、より効率的にス
リットで弾性表面波を反射させることが可能となるため、弾性表面波エネルギーの閉じ込めに更に優れた高性能の弾性表面波装置とすることが出来る。 Furthermore, according to the surface acoustic wave device of the present invention, a plurality of the slits are formed in each of the bus bar electrodes and / or the common electrode, and the arrangement pitch is made smaller than the arrangement pitch of the electrode fingers. In this case, a part of the surface acoustic wave that leaks due to the deviation of the traveling direction due to diffraction can be Bragg reflected by a plurality of slits, and the surface acoustic wave can be reflected more efficiently by the slit. Therefore, it is possible to provide a high-performance surface acoustic wave device further excellent in confining surface acoustic wave energy.

以下、本発明の弾性表面波装置を図面に基づいて詳説する。   Hereinafter, the surface acoustic wave device of the present invention will be described in detail with reference to the drawings.

図１は本発明の一実施形態に係る弾性表面波装置を模式的に示す外観斜視図である。同図に示す弾性表面波装置は、圧電基板１０の上面に、弾性表面波の伝搬方向に沿って配置される一対の反射器２０、及びその間に配置されるＩＤＴ３０、更にＩＤＴ３０と接続されて外部との電気的接続に供されるパッド電極４０等から成る各種電極を形成した構造を有している。   FIG. 1 is an external perspective view schematically showing a surface acoustic wave device according to an embodiment of the present invention. The surface acoustic wave device shown in FIG. 1 is connected to the pair of reflectors 20 arranged along the propagation direction of the surface acoustic wave on the upper surface of the piezoelectric substrate 10, the IDT 30 arranged therebetween, and further connected to the IDT 30. Are formed with various electrodes including a pad electrode 40 and the like for electrical connection.

圧電基板１０は、例えば、水晶、タンタル酸リチウム単結晶、ニオブ酸リチウム単結晶、四ホウ酸リチウム単結晶等の圧電性の単結晶、或いはチタン酸鉛、ジルコン酸鉛等の圧電セラミックスから成り、その上面で上記各種電極を支持する支持母材として機能するとともに、ＩＤＴ３０を介して圧電基板１０に電気信号が印加されると、その一主面で所定の弾性表面波を発生させる作用を為す。   The piezoelectric substrate 10 is made of, for example, piezoelectric single crystal such as crystal, lithium tantalate single crystal, lithium niobate single crystal, lithium tetraborate single crystal, or piezoelectric ceramics such as lead titanate and lead zirconate, In addition to functioning as a support base material that supports the various electrodes on its upper surface, when an electric signal is applied to the piezoelectric substrate 10 via the IDT 30, it acts to generate a predetermined surface acoustic wave on its principal surface.

ＩＤＴ３０は、弾性表面波の伝搬方向に沿って等間隔に配設した複数の電極指３１の一端を帯状のバスバー電極３２で接続してなる一対の櫛歯状電極を、それぞれの電極指３１が弾性表面波の伝搬方向に交互に配置されるようにかみ合わせた状態で対向配置させて構成されている。そして、外部から所定の電気信号が印加されると、圧電基板１０の上面に電極指３１の配列ピッチに対応した所定の弾性表面波を発生させる作用を為す。   The IDT 30 includes a pair of comb-like electrodes formed by connecting one ends of a plurality of electrode fingers 31 arranged at equal intervals along the propagation direction of the surface acoustic wave with a strip-shaped bus bar electrode 32. They are arranged so as to face each other in an interlocked state so as to be alternately arranged in the propagation direction of the surface acoustic wave. When a predetermined electrical signal is applied from the outside, a predetermined surface acoustic wave corresponding to the arrangement pitch of the electrode fingers 31 is generated on the upper surface of the piezoelectric substrate 10.

一方、反射器２０は、弾性表面波の伝搬方向に沿ってＩＤＴ３０の電極指３１とほぼ同じピッチで等間隔に配設した複数の反射電極２１の両端を、共通電極２２で接続して構成されている。そして、ＩＤＴ３０の形成領域で発生する弾性表面波を反射して、一対の反射器２０の間に閉じ込める作用を為す。   On the other hand, the reflector 20 is configured by connecting both ends of a plurality of reflective electrodes 21 arranged at equal intervals at substantially the same pitch as the electrode fingers 31 of the IDT 30 along the propagation direction of the surface acoustic wave by the common electrode 22. ing. The surface acoustic wave generated in the IDT 30 formation region is reflected and confined between the pair of reflectors 20.

そして、パッド電極４０は、外部との電気的接続をなす金属細線やバンプが接合される部分であり、ＩＤＴ３０と電気的に接続されている。   The pad electrode 40 is a portion to which fine metal wires and bumps that are electrically connected to the outside are joined, and is electrically connected to the IDT 30.

尚、上記各種電極は、例えば、アルミニウムやアルミニウムを主成分とする合金等の金属材料から成り、蒸着やスパッタリングによって圧電基板１０上に形成した電極膜上にレジストをスピンコートし、ステッパー装置などを用いて露光・現像した後に、ＲＩＥ（Ｒｅａｃｔｉｖｅ Ｉｏｎ Ｅｔｃｈｉｎｇ）装置などを用いてエッチングすることによって形成される。パッド電極４０については、金属細線やバンプとの接合性を向上させるために、上面をＮｉ、Ｃｒ、Ａｕ等で被覆するとよく、厚みも他の電極よりも厚い方がよい。   The various electrodes are made of, for example, a metal material such as aluminum or an alloy containing aluminum as a main component. A resist is spin-coated on an electrode film formed on the piezoelectric substrate 10 by vapor deposition or sputtering, and a stepper device or the like is provided. It is formed by etching using a RIE (Reactive Ion Etching) apparatus or the like after exposure and development. The pad electrode 40 may be covered with Ni, Cr, Au or the like on the upper surface in order to improve the bondability with a fine metal wire or bump, and the thickness is preferably thicker than other electrodes.

こうして、一対の反射器２０と、その間に配置されるＩＤＴ３０とで弾性表面波共振器が構成されている。   Thus, a surface acoustic wave resonator is constituted by the pair of reflectors 20 and the IDT 30 disposed therebetween.

本実施形態の特徴的なところは、電極指３１と垂直な複数のスリット３３を、ＩＤＴ３０のバスバー電極３２に等間隔に形成し、また、電極指３１と垂直な複数のスリット２３を、反射器２０の共通電極２２に等間隔に形成したことである。   A characteristic feature of this embodiment is that a plurality of slits 33 perpendicular to the electrode fingers 31 are formed in the bus bar electrode 32 of the IDT 30 at equal intervals, and a plurality of slits 23 perpendicular to the electrode fingers 31 are provided as reflectors. That is, the 20 common electrodes 22 are formed at equal intervals.

上述したような弾性表面波装置においては、ＩＤＴ３０で発生した弾性表面波の大部分は、電極指３１と垂直な方向（電極指３１の配列方向）に伝搬し、一対の反射器２０間で多重反射して閉じ込められる。ところが、一部の弾性表面波は回折によってその伝搬方向が変化し、ＩＤＴ３０のバスバー電極３２や反射器２０の共通電極２２を通過して、弾性表面波装置の外部へ漏洩してしまい、弾性表面波装置の電気特性を劣化させていた。   In the surface acoustic wave device as described above, most of the surface acoustic waves generated by the IDT 30 propagate in the direction perpendicular to the electrode fingers 31 (the direction in which the electrode fingers 31 are arranged) and are multiplexed between the pair of reflectors 20. Reflected and trapped. However, the propagation direction of some surface acoustic waves changes due to diffraction, passes through the bus bar electrode 32 of the IDT 30 and the common electrode 22 of the reflector 20, and leaks to the outside of the surface acoustic wave device. The electrical characteristics of the wave device were deteriorated.

本実施形態の弾性表面波装置においては、バスバー電極３２にスリット３３を、共通電極２２にスリット２３をそれぞれ形成しているので、外部へ漏洩しようとする弾性表面波をスリット２３、３３で反射して弾性表面波装置内に閉じ込めることが可能となる。   In the surface acoustic wave device of this embodiment, the slit 33 is formed in the bus bar electrode 32 and the slit 23 is formed in the common electrode 22, so that the surface acoustic wave to be leaked to the outside is reflected by the slits 23 and 33. Thus, it can be confined in the surface acoustic wave device.

スリット２３、３３における弾性表面波の反射は、反射電極２１における反射と同様のメカニズムによってスリット２３、３３の両側面で発生する。よって反射量を向上させるためには多数のスリット２３、３３を形成すれば良く、また、スリット１本あたりの反射量を増加させるためには、バスバー電極３２及び共通電極２２の厚みを厚くするのが望ましい。   The reflection of the surface acoustic waves at the slits 23 and 33 is generated on both side surfaces of the slits 23 and 33 by the same mechanism as the reflection at the reflective electrode 21. Therefore, a large number of slits 23 and 33 may be formed in order to improve the reflection amount, and in order to increase the reflection amount per slit, the thickness of the bus bar electrode 32 and the common electrode 22 is increased. Is desirable.

また、スリット２３、３３の配列ピッチは電極指３１の配列ピッチとほぼ同程度とすれば良く、スリット２３、３３の幅は電極指３１の配列ピッチの１／２とほぼ同程度とすれば良いが、更に望ましくは、スリット２３、３３の配列ピッチを電極指３１の配列ピッチよりも小さくし、スリット２３、３３の幅はスリット２３、３３の配列ピッチのほぼ1／２とする。（スリット２３、３３の幅は電極指３１の配列ピッチの１／２よりも小さくする。）
これは、スリット２３、３３に対して斜めに入射して来る弾性表面波を効率よく反射させるためである。例えば、スリット２３、３３に垂直な方向に対して角度Ａで入射する弾性表面波をブラッグ反射させるためには、スリット２３、３３の配列ピッチは電極指３１の配列ピッチの１／ｃｏｓＡ、スリット２３、３３の幅は電極指３１の配列ピッチの１／（２ｃｏｓＡ）とすればよい。弾性表面波はスリット２３、３３に対して様々な角度で入射して来るために全ての弾性表面波をブラッグ反射させる事は不可能であるが、スリット２３、３３の配列ピッチを電極指３１の配列ピッチよりも小さくしておくことにより、ある特定の角度で入射して来る弾性表面波をブラッグ反射させることができ、弾性表面波を効率的に反射することが可能となる。 The arrangement pitch of the slits 23 and 33 may be approximately the same as the arrangement pitch of the electrode fingers 31, and the width of the slits 23 and 33 may be approximately the same as ½ of the arrangement pitch of the electrode fingers 31. More preferably, however, the arrangement pitch of the slits 23 and 33 is made smaller than the arrangement pitch of the electrode fingers 31, and the width of the slits 23 and 33 is approximately ½ of the arrangement pitch of the slits 23 and 33. (The width of the slits 23 and 33 is set to be smaller than ½ of the arrangement pitch of the electrode fingers 31.)
This is to efficiently reflect the surface acoustic wave incident obliquely on the slits 23 and 33. For example, in order to Bragg-reflect surface acoustic waves incident at an angle A with respect to a direction perpendicular to the slits 23 and 33, the arrangement pitch of the slits 23 and 33 is 1 / cosA of the arrangement pitch of the electrode fingers 31, and the slit 23 , 33 may be 1 / (2 cos A) of the arrangement pitch of the electrode fingers 31. Since the surface acoustic waves are incident on the slits 23 and 33 at various angles, it is impossible to Bragg-reflect all the surface acoustic waves. By making it smaller than the arrangement pitch, the surface acoustic wave incident at a specific angle can be Bragg reflected, and the surface acoustic wave can be efficiently reflected.

スリット２３、３３に対する弾性表面波の入射角度の分布は、圧電基板１０の材質や、ＩＤＴ３０の電極指３１の対数、交差幅、配列ピッチ、開口長など、及び、反射器２０の反射電極２１の本数、開口長、配列ピッチなど各種設計事項によって変化するので、スリット２３、３３の配列ピッチ及び幅については、それに応じて適切な値に設定する。   The distribution of the angle of incidence of the surface acoustic wave on the slits 23 and 33 is such that the material of the piezoelectric substrate 10, the logarithm of the electrode fingers 31 of the IDT 30, the crossing width, the array pitch, the opening length, etc. Since it varies depending on various design matters such as the number, opening length, and arrangement pitch, the arrangement pitch and width of the slits 23 and 33 are set to appropriate values accordingly.

また、ＩＤＴ３０におけるスリット３３に対する弾性表面波の入射角度の分布と、反射器２０におけるスリット２３に対する弾性表面波の入射角度の分布とは異なるので、スリット３３の配列ピッチ及び幅とスリット２３の配列ピッチ及び幅とを異ならせる事により、より効率的に弾性表面波を反射させることが可能となる。一般的には、ＩＤＴ３０のスリット３３に対する弾性表面波の入射角度よりも、反射器２０のスリット２３に対する弾性表面波の入射角度の方が深くなりやすい。よって、反射器２０のスリット２３の配列ピッチ及び幅を、ＩＤＴ３０のスリット３３の配列ピッチ及び幅よりも小さくすることによって、より効率的に弾性表面波を反射させることができる。   Further, since the distribution of the surface acoustic wave incident angle with respect to the slit 33 in the IDT 30 and the surface acoustic wave incident angle distribution with respect to the slit 23 in the reflector 20 are different, the arrangement pitch and width of the slit 33 and the arrangement pitch of the slit 23 And by making the widths different, it becomes possible to reflect the surface acoustic wave more efficiently. In general, the incident angle of the surface acoustic wave to the slit 23 of the reflector 20 tends to be deeper than the incident angle of the surface acoustic wave to the slit 33 of the IDT 30. Therefore, by making the arrangement pitch and width of the slits 23 of the reflector 20 smaller than the arrangement pitch and width of the slits 33 of the IDT 30, surface acoustic waves can be reflected more efficiently.

尚、スリット２３、３３の形成は、前述した、蒸着やスパッタリングによって圧電基板１０上に形成した電極膜上にレジストをコートし、露光、現像、エッチングして各種電極を形成するときに同時に行えばよく、これによって製造設備や製造工程が増加することはない。   The slits 23 and 33 can be formed at the same time as forming the various electrodes by coating a resist on the electrode film formed on the piezoelectric substrate 10 by vapor deposition or sputtering and exposing, developing and etching. Well, this does not increase manufacturing equipment or manufacturing processes.

次に本発明の他の実施形態に係る弾性表面波装置について図２を用いて説明する。尚、本実施形態においては先に述べた実施形態と異なる点についてのみ説明し、同様の構成要素については同一の参照符を用いて重複する説明を省略するものとする。   Next, a surface acoustic wave device according to another embodiment of the present invention will be described with reference to FIG. In the present embodiment, only differences from the above-described embodiment will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.

図２は本実施形態の弾性表面波装置を模式的に示す外観斜視図である。本実施形態の弾性表面波装置が先に述べた実施形態の弾性表面波装置と異なる点は、ＩＤＴ３０に形成された個々のスリット３３が、電極指３１と垂直な複数のスリット片３３ａをその長辺方向に一列状に配列して構成されていることである。このような構造とすることによって、それぞれの電極指３１とパッド電極４０とを接続する電気的経路が増加し、電気抵抗による損失を低減することができる。   FIG. 2 is an external perspective view schematically showing the surface acoustic wave device of the present embodiment. The surface acoustic wave device of this embodiment is different from the surface acoustic wave device of the above-described embodiment in that each slit 33 formed in the IDT 30 has a plurality of slit pieces 33a perpendicular to the electrode fingers 31. That is, they are arranged in a line in the side direction. With such a structure, the electrical path connecting each electrode finger 31 and the pad electrode 40 increases, and loss due to electrical resistance can be reduced.

尚、本発明は上述の実施形態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において種々の変更、改良が可能である。   In addition, this invention is not limited to the above-mentioned embodiment, A various change and improvement are possible in the range which does not deviate from the summary of this invention.

例えば、上述した弾性表面波装置においては、圧電基板１０及び上記各種電極の上に被覆層が形成されていない例を示したが、絶縁材料もしくは半導電性材料からなる被覆層を形成しても構わない。   For example, in the surface acoustic wave device described above, an example in which a coating layer is not formed on the piezoelectric substrate 10 and the various electrodes has been shown, but a coating layer made of an insulating material or a semiconductive material may be formed. I do not care.

また、上述した実施形態においては弾性表面波共振器を構成した例を示したが、弾性表面波フィルタや、それを用いたデュプレクサなど、他の弾性表面波装置においても本発明を適用できることは言うまでもない。   In the above-described embodiment, an example in which a surface acoustic wave resonator is configured has been described. Needless to say, the present invention can also be applied to other surface acoustic wave devices such as a surface acoustic wave filter and a duplexer using the surface acoustic wave filter. Yes.

本発明の一実施形態に係る弾性表面波装置を模式的に示す外観斜視図である。1 is an external perspective view schematically showing a surface acoustic wave device according to an embodiment of the present invention. 本発明の別の実施形態に係る弾性表面波装置を模式的に示す外観斜視図である。It is an external appearance perspective view which shows typically the surface acoustic wave apparatus which concerns on another embodiment of this invention.

符号の説明Explanation of symbols

１０・・・圧電基板
２０・・・反射器
２１・・・反射電極
２２・・・共通電極
３０・・・ＩＤＴ
３１・・・電極指
３２・・・バスバー電極
２３、３３・・・スリット
３３ａ・・・スリット片
４０・・・パッド電極 DESCRIPTION OF SYMBOLS 10 ... Piezoelectric substrate 20 ... Reflector 21 ... Reflective electrode 22 ... Common electrode 30 ... IDT
31 ... Electrode finger 32 ... Bus bar electrode 23, 33 ... Slit 33a ... Slit piece 40 ... Pad electrode

Claims (5)

圧電基板上に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の電極指の一端をバスバー電極で接続してなる一対の櫛歯状電極を、前記電極指が互いに噛み合うように対向させてなるＩＤＴを形成するとともに、該ＩＤＴの弾性表面波の伝搬方向の両側に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の反射電極の両端を共通電極で接続してなる一対の反射器を形成してなる弾性表面波装置において、
前記一対のバスバー電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成したことを特徴とする弾性表面波装置。 A pair of comb-like electrodes formed by connecting one end of a plurality of electrode fingers arranged at equal intervals along the propagation direction of the surface acoustic wave on the piezoelectric substrate with bus bar electrodes so that the electrode fingers mesh with each other. In addition to forming IDTs facing each other, both ends of a plurality of reflective electrodes arranged at equal intervals along the surface acoustic wave propagation direction are connected to both sides of the IDT surface acoustic wave propagation direction by a common electrode. In the surface acoustic wave device formed by forming a pair of reflectors,
2. A surface acoustic wave device according to claim 1, wherein at least one slit is formed in each of the pair of bus bar electrodes perpendicular to the plurality of electrode fingers. 圧電基板上に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の電極指の一端をバスバー電極で接続してなる一対の櫛歯状電極を、前記電極指が互いに噛み合うように対向させてなるＩＤＴを形成するとともに、該ＩＤＴの弾性表面波の伝搬方向の両側に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の反射電極の両端を一対の共通電極で接続してなる一対の反射器を形成してなる弾性表面波装置において、
前記一対の共通電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成したことを特徴とする弾性表面波装置。 A pair of comb-like electrodes formed by connecting one end of a plurality of electrode fingers arranged at equal intervals along the propagation direction of the surface acoustic wave on the piezoelectric substrate with bus bar electrodes so that the electrode fingers mesh with each other. The IDT is formed so as to face each other, and both ends of a plurality of reflective electrodes arranged at equal intervals along the propagation direction of the surface acoustic wave on both sides of the surface acoustic wave propagation direction of the IDT are a pair of common electrodes. In the surface acoustic wave device formed by forming a pair of reflectors connected,
A surface acoustic wave device, wherein at least one slit is formed in each of the pair of common electrodes perpendicularly to the plurality of electrode fingers. 圧電基板上に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の電極指の一端をバスバー電極で接続してなる一対の櫛歯状電極を、前記電極指が互いに噛み合うように対向させてなるＩＤＴを形成するとともに、該ＩＤＴの弾性表面波の伝搬方向の両側に、弾性表面波の伝搬方向に沿って等間隔に配設した複数の反射電極の両端を一対の共通電極で接続してなる一対の反射器を形成してなる弾性表面波装置において、
前記一対のバスバー電極と前記一対の共通電極のそれぞれに、少なくとも一本のスリットを、前記複数の電極指と垂直に形成したことを特徴とする弾性表面波装置。 A pair of comb-like electrodes formed by connecting one end of a plurality of electrode fingers arranged at equal intervals along the propagation direction of the surface acoustic wave on the piezoelectric substrate with bus bar electrodes so that the electrode fingers mesh with each other. The IDT is formed so as to face each other, and both ends of a plurality of reflective electrodes arranged at equal intervals along the propagation direction of the surface acoustic wave on both sides of the surface acoustic wave propagation direction of the IDT are a pair of common electrodes. In the surface acoustic wave device formed by forming a pair of reflectors connected,
2. A surface acoustic wave device according to claim 1, wherein at least one slit is formed in each of the pair of bus bar electrodes and the pair of common electrodes perpendicular to the plurality of electrode fingers. 前記スリットの幅が前記電極指の配列ピッチの１／２より小さくされていることを特徴とする請求項１乃至３に記載の弾性表面波装置。   4. The surface acoustic wave device according to claim 1, wherein a width of the slit is smaller than ½ of an arrangement pitch of the electrode fingers. 前記スリットがそれぞれの前記バスバー電極及び／又は前記共通電極に複数本形成されており、その配列ピッチが前記電極指の配列ピッチより小さくされていることを特徴とする請求項１乃至４に記載の弾性表面波装置。   The said slit is formed in each said bus-bar electrode and / or the said common electrode, and the arrangement pitch is made smaller than the arrangement pitch of the said electrode finger, The Claim 1 thru | or 4 characterized by the above-mentioned. Surface acoustic wave device.
JP2004343097A 2004-11-26 2004-11-26 Surface acoustic wave device Expired - Fee Related JP4557691B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2004343097A JP4557691B2 (en) 2004-11-26 2004-11-26 Surface acoustic wave device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004343097A JP4557691B2 (en) 2004-11-26 2004-11-26 Surface acoustic wave device

Publications (2)

Publication Number Publication Date
JP2006157307A JP2006157307A (en) 2006-06-15
JP4557691B2 true JP4557691B2 (en) 2010-10-06

Family

ID=36635077

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2004343097A Expired - Fee Related JP4557691B2 (en) 2004-11-26 2004-11-26 Surface acoustic wave device

Country Status (1)

Country Link
JP (1) JP4557691B2 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5039362B2 (en) * 2006-11-07 2012-10-03 太陽誘電株式会社 Elastic wave device
JP5135838B2 (en) * 2007-03-23 2013-02-06 凸版印刷株式会社 Surface acoustic wave device
JP5872196B2 (en) * 2011-06-29 2016-03-01 京セラ株式会社 Elastic wave device and elastic wave device using the same
JP5882842B2 (en) * 2012-01-31 2016-03-09 京セラ株式会社 Surface acoustic wave element and surface acoustic wave device
JP6401088B2 (en) * 2015-03-18 2018-10-03 太陽誘電株式会社 Elastic wave device
JP6421748B2 (en) * 2015-12-25 2018-11-14 株式会社村田製作所 Elastic wave device
DE102018131952A1 (en) 2018-12-12 2020-06-18 RF360 Europe GmbH Electroacoustic resonator with suppressed excitation of transverse slit modes and reduced transverse modes
CN113364421A (en) * 2021-06-03 2021-09-07 成都频岢微电子有限公司 Surface acoustic wave resonator, filter, and antenna duplexer

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10145173A (en) * 1996-11-11 1998-05-29 Fujitsu Ltd Interdigital transducer and surface acoustic wave multiplex mode filter
JPH11261370A (en) * 1998-03-11 1999-09-24 Nec Corp Surface acoustic wave device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10145173A (en) * 1996-11-11 1998-05-29 Fujitsu Ltd Interdigital transducer and surface acoustic wave multiplex mode filter
JPH11261370A (en) * 1998-03-11 1999-09-24 Nec Corp Surface acoustic wave device

Also Published As

Publication number Publication date
JP2006157307A (en) 2006-06-15

Similar Documents

Publication Publication Date Title
US10833649B2 (en) Acoustic wave element and communication apparatus
CN111510106A (en) Surface acoustic wave resonant structure filter
JP3897229B2 (en) Surface wave filter
US20140145557A1 (en) Acoustic wave element and acoustic wave device using same
US7728699B2 (en) Acoustic wave filter
JP4569447B2 (en) Surface acoustic wave element and surface acoustic wave device
US20220216846A1 (en) Acoustic wave device
JP5338914B2 (en) Elastic wave device, duplexer and electronic device using the same
CN114531136A (en) Surface acoustic wave resonator and surface acoustic wave filter having the same
JP4557691B2 (en) Surface acoustic wave device
CN113519120B (en) Elastic wave device
JP5815383B2 (en) Elastic wave device and elastic wave device using the same
CN115102522A (en) Surface acoustic wave resonator and surface acoustic wave filter
JP4601416B2 (en) Surface acoustic wave device
JP2002152003A (en) Surface acoustic wave filter
JP5872196B2 (en) Elastic wave device and elastic wave device using the same
JP4214009B2 (en) Surface acoustic wave device
WO2010125940A1 (en) Elastic wave device
JP2004350255A (en) Surface acoustic wave device
WO2021117581A1 (en) Elastic wave device
JP3435868B2 (en) Edge reflection type surface acoustic wave device and method of manufacturing the same
JPH02250412A (en) Surface acoustic wave device
JP4024224B2 (en) Surface acoustic wave device
JP2004007846A (en) Surface acoustic wave resonator
JP5882842B2 (en) Surface acoustic wave element and surface acoustic wave device

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20071019

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20100413

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20100517

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20100622

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20100720

R150 Certificate of patent or registration of utility model

Ref document number: 4557691

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130730

Year of fee payment: 3

LAPS Cancellation because of no payment of annual fees