JPH03173211A - Surface acoustic wave device - Google Patents
Surface acoustic wave deviceInfo
- Publication number
- JPH03173211A JPH03173211A JP31361889A JP31361889A JPH03173211A JP H03173211 A JPH03173211 A JP H03173211A JP 31361889 A JP31361889 A JP 31361889A JP 31361889 A JP31361889 A JP 31361889A JP H03173211 A JPH03173211 A JP H03173211A
- Authority
- JP
- Japan
- Prior art keywords
- wave device
- comb
- electrodes
- piezoelectric substrate
- absorber
- 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.)
- Pending
Links
- 238000010897 surface acoustic wave method Methods 0.000 title 1
- 239000000758 substrate Substances 0.000 claims abstract description 14
- 239000004925 Acrylic resin Substances 0.000 claims abstract description 5
- 229920000178 Acrylic resin Polymers 0.000 claims abstract description 5
- 229910052751 metal Inorganic materials 0.000 claims abstract description 3
- 239000002184 metal Substances 0.000 claims abstract description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 238000000605 extraction Methods 0.000 claims description 3
- 239000011347 resin Substances 0.000 claims description 2
- 229920005989 resin Polymers 0.000 claims description 2
- 239000004593 Epoxy Substances 0.000 claims 1
- 239000006096 absorbing agent Substances 0.000 abstract description 8
- 239000003822 epoxy resin Substances 0.000 abstract description 5
- 229920000647 polyepoxide Polymers 0.000 abstract description 5
- 230000000694 effects Effects 0.000 description 5
- 239000013078 crystal Substances 0.000 description 2
- 238000000206 photolithography Methods 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、テレビジョン受像機、ビデオテープレコーダ
等の映像機器、ポケットベル等の通信機器、及びセキュ
リティ関連のトランスミッタ用発振回路等に使用される
表面波デイバイスに関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to surfaces used in video equipment such as television receivers and video tape recorders, communication equipment such as pagers, and oscillation circuits for security-related transmitters. It concerns wave devices.
従来の技術
以下に従来の表面波デイバイスについて説明する。第6
図は、従来の表面波デイバイスの圧電体の構成を示す平
面図である。第5図において単結晶の圧電基板1の主平
面の全面にアルミニウムを蒸着した後、フォトリソグラ
フィ法により引出電極2と3、くし形電極4と6及びア
ース電極6を設け、圧電基板1の両端にエポキシ樹脂又
はアクリル樹脂を塗布してアブソーバ7を設ける。第2
図は、表面波デイバイスの構成を示す平面図、第3図は
その平面断面図である。第2図及び第3図において圧電
基板1をステム8上に電極面を上にしてエポキシ樹脂9
で貼りつけ、引出電極2及び3と金属製のステム8の端
子1oをアルミニウム線11を用いて結線する。アース
電極6もステム7にアルミニウム線11で接地し、キャ
ップ12をステム7の上にかぶせ、ステム7とキャップ
12を溶接して気密封止する構成である。BACKGROUND OF THE INVENTION A conventional surface wave device will be described below. 6th
The figure is a plan view showing the configuration of a piezoelectric body of a conventional surface wave device. In FIG. 5, aluminum is deposited on the entire main plane of a single crystal piezoelectric substrate 1, and then lead electrodes 2 and 3, comb-shaped electrodes 4 and 6, and a ground electrode 6 are provided by photolithography, and both ends of the piezoelectric substrate 1 are The absorber 7 is provided by applying epoxy resin or acrylic resin. Second
The figure is a plan view showing the structure of the surface wave device, and FIG. 3 is a plan cross-sectional view thereof. In FIGS. 2 and 3, the piezoelectric substrate 1 is placed on the stem 8 with the electrode surface facing up, and the epoxy resin 9
The lead electrodes 2 and 3 and the terminal 1o of the metal stem 8 are connected using an aluminum wire 11. The earth electrode 6 is also grounded to the stem 7 with an aluminum wire 11, a cap 12 is placed over the stem 7, and the stem 7 and the cap 12 are welded to form an airtight seal.
発明が解決しようとする課題
しかしながら上記の従来の構成では、圧電基板の厚み方
向に伝播したバルク波が高帯域のトラップ部分に重なる
ので、高帯域のトラップの減衰量が小さくなるという問
題点を有していた。Problems to be Solved by the Invention However, the conventional configuration described above has a problem in that the bulk wave propagated in the thickness direction of the piezoelectric substrate overlaps the high band trap portion, resulting in a small attenuation amount of the high band trap. Was.
本発明は上記従来の問題点を解決するもので高帯域のト
ラップ減衰量が大きい表面波デイバイスを提供すること
を目的とする。The present invention solves the above-mentioned conventional problems and aims to provide a surface wave device having a large amount of trap attenuation in a high band.
課題を解決するための手段
この目的を達成するために本発明の表面波デイバイスは
、くし形電極の主交差部分で、引出電極から交差部分の
中央位に向かって、交差幅の3分の1以下の部分にエポ
キシ樹脂又はアクリル樹脂を塗布した構成を有している
。Means for Solving the Problems To achieve this object, the surface wave device of the present invention provides a surface wave device of the present invention in which, at the main intersection of the comb-shaped electrodes, from the extraction electrode toward the center of the intersection, one-third of the intersection width is It has a structure in which the following parts are coated with epoxy resin or acrylic resin.
作用
この構成によって、圧電基板の厚み方向に伝播するバル
ク波の振動を減衰させることができ、周波数特性のトラ
ップ減衰量を大きくすることができる。Effect: With this configuration, it is possible to attenuate the vibration of the bulk wave propagating in the thickness direction of the piezoelectric substrate, and it is possible to increase the amount of trap attenuation of the frequency characteristic.
実施例
以下本発明の一実施例について、図面を参照しながら説
明する。第1図は本発明の実施例における表面波デイバ
イスの圧電体の構成を示す平面図である。EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the structure of a piezoelectric body of a surface wave device in an embodiment of the present invention.
第1図において単結晶の圧電基板13の主平面を研磨し
、その研磨面にアルミニウムを蒸着する。In FIG. 1, the main plane of a single-crystal piezoelectric substrate 13 is polished, and aluminum is deposited on the polished surface.
蒸着したアルミニウムをフォトリングラフィ法によりエ
ツチングし、引出電極2,3とくし形電極4.5及びア
ース電極6を設ける。その後、エポキシ樹脂又はアクリ
ル樹脂を第1図に示すように正規型のくし形電極5の交
差している部分の引出電極から中央に向かって3分の1
以下の部分に塗布してアブソーバ14を形成する。圧電
基板13で、上記の処理を施した部分と反対側の部分に
は、くし形電極4にかからないように上記と同じ樹脂を
塗布してアブソーバ7を形成させる。The vapor-deposited aluminum is etched by photolithography to provide extraction electrodes 2, 3, interdigitated electrodes 4.5, and ground electrode 6. Then, as shown in FIG.
The absorber 14 is formed by coating the following parts. The absorber 7 is formed by applying the same resin as above to the piezoelectric substrate 13 on the opposite side to the part subjected to the above treatment so as not to cover the comb-shaped electrodes 4.
以上の処理をした圧電基板13を第2図及び第3図で説
明したように従来の表面波デイバイスと同様に組立てる
。The piezoelectric substrate 13 subjected to the above treatment is assembled in the same manner as a conventional surface wave device as explained in FIGS. 2 and 3.
表面波デイバイスでは、外部リード端子10を経てくし
形電極4に印加された電気信号は圧電基板13のもつ圧
電効果にょ夛、機械振動に変換されこの機械振動は圧電
基板13の主平面上をもう一方のくし形電極6にむかっ
て伝播する。くし形電極6に達した機械振動は、圧電効
果にょシ今度は電気振動に変換される。In the surface wave device, an electrical signal applied to the comb-shaped electrode 4 via the external lead terminal 10 is converted into mechanical vibration due to the piezoelectric effect of the piezoelectric substrate 13, and this mechanical vibration is transmitted over the main plane of the piezoelectric substrate 13. It propagates toward one of the comb-shaped electrodes 6. The mechanical vibrations that reach the comb-shaped electrodes 6 are converted into electrical vibrations due to the piezoelectric effect.
従来の表面波デイバイスでは、第5図において、くし形
電極4で、電気信号から機械振動に変換された信号波の
うち圧電基板13の厚み方向に伝播した波(バルク波)
が、圧電基板1のくし形電極4を構成した面と反対の面
で反射し、くし形電極6に達する。このバルク波が、電
気信号に変換されると第4図に示す波形イのように、高
城のトラップ部分に丁度バルク波が重なりトラップ減衰
量が設計値より小さくなってしまう。In the conventional surface wave device, in FIG. 5, among the signal waves converted from electrical signals to mechanical vibrations by the comb-shaped electrode 4, waves (bulk waves) propagated in the thickness direction of the piezoelectric substrate 13 are generated.
is reflected from the surface of the piezoelectric substrate 1 opposite to the surface on which the comb-shaped electrodes 4 are formed, and reaches the comb-shaped electrodes 6. When this bulk wave is converted into an electric signal, as shown in waveform A shown in FIG. 4, the bulk wave overlaps exactly with the trap portion of Takagi, and the amount of trap attenuation becomes smaller than the designed value.
本発明では、第1図において、くし形電極6の電極が交
差している部分のうち、引出電極から中央に向かって3
分の1以下の部分にエポキシ樹脂又はアクリル樹脂を塗
布したアブソーバ14でバルク波の振動を減衰させるこ
とにより、電気信号に変換される信号レベルをさげるこ
とができる。In the present invention, in FIG. 1, among the parts where the electrodes of the comb-shaped electrode 6 intersect, three
By attenuating the vibration of the bulk wave using the absorber 14 whose portion is coated with epoxy resin or acrylic resin, the signal level converted into an electrical signal can be lowered.
こうしてバルク波の影響を無くし、第4図に示す波形口
を得ることができる。In this way, the influence of bulk waves can be eliminated and the waveform opening shown in FIG. 4 can be obtained.
なお、くし形電極の4と6で電極の交差幅が異なると、
挿入損失が増加するなどの現象が生ずるため、くシ形電
極6の交差幅をくし形電極4の交差幅より大きくすると
よい。大きくする寸法は。In addition, if the intersecting width of the electrodes 4 and 6 of the comb-shaped electrodes is different,
Since phenomena such as an increase in insertion loss occur, the width of the intersection of the comb-shaped electrodes 6 is preferably made larger than the width of the intersection of the comb-shaped electrodes 4. What are the dimensions to increase?
上記処理を実施したときアブソーバがくし形電極の交差
部分にかかっているだけの寸法とする。The dimensions are such that the absorber covers the intersection of the comb-shaped electrodes when the above process is carried out.
発明の効果
以上のように本発明は、くし形電極の主交差部分にアブ
ソーバを設けることにより、バルク波の影響が除去でき
、実装回路の簡略化を計ることができる優れた表面波デ
イバイスを実現できるものである。Effects of the Invention As described above, the present invention realizes an excellent surface wave device in which the effects of bulk waves can be removed and the mounting circuit can be simplified by providing an absorber at the main intersection of the comb-shaped electrodes. It is possible.
第1図は本発明の一実施例における表面波デイバイスの
圧電体の構成を示す平面図、第2図は表面波デイバイス
の構成を示す平面図、第3図はその平面断面図、第4図
は従来と本実施例の周波数特性のトラップ減衰量を示す
グラフ、第6図は従来の表面波デイバイスの圧電体の構
成を示す平面図である。FIG. 1 is a plan view showing the structure of a piezoelectric body of a surface wave device according to an embodiment of the present invention, FIG. 2 is a plan view showing the structure of the surface wave device, FIG. 3 is a plan cross-sectional view thereof, and FIG. 6 is a graph showing the amount of trap attenuation of the frequency characteristics of the conventional surface wave device and the present embodiment, and FIG. 6 is a plan view showing the structure of the piezoelectric body of the conventional surface wave device.
Claims (1)
設け、くし形電極の主交差部分で、引出電極から交差部
分の中央位に向かって、交差幅の3分の1以下の部分に
エポキシ樹脂又はアクリル樹脂を塗布し、周波数特性の
トラップ減衰量を大きくした表面波ディバイス。A comb-shaped electrode made of metal such as aluminum is provided on the piezoelectric substrate, and at the main intersection of the comb-shaped electrode, epoxy is applied to a portion of one-third or less of the intersection width from the extraction electrode toward the center of the intersection. A surface wave device coated with resin or acrylic resin to increase trap attenuation in frequency characteristics.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP31361889A JPH03173211A (en) | 1989-12-01 | 1989-12-01 | Surface acoustic wave device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP31361889A JPH03173211A (en) | 1989-12-01 | 1989-12-01 | Surface acoustic wave device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH03173211A true JPH03173211A (en) | 1991-07-26 |
Family
ID=18043488
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP31361889A Pending JPH03173211A (en) | 1989-12-01 | 1989-12-01 | Surface acoustic wave device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH03173211A (en) |
-
1989
- 1989-12-01 JP JP31361889A patent/JPH03173211A/en active Pending
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