SURFACE ACOUSTIC WAVE SENSOR AND MANUFACTURING METHOD FOR SURFACE ACOUSTIC WAVE SENSOR

To provide a manufacturing method for a surface acoustic wave sensor that minimizes a propagation loss.SOLUTION: Provided is a surface acoustic wave sensor S comprising: a comb-shaped electrode 2 for transmitting/receiving or reflecting a surface acoustic wave; a detection region 3 into which a liquid to be measured is introduced; and an encapsulation dam 4 formed somewhere on a comb-shaped electrode 2 near the boundary between the comb-shaped electrode 2 and the detection region 3 (i.e., on a dummy electrode), for preventing the ingress of the liquid to be measured from entering the comb-shaped electrode 2 from the detection region 3. A metalize ratio M that is the ratio, to the sum of the width of an electrode finger formed with a metal film and the width between adjacent electrode fingers where no metal film is formed, out of the comb-shaped electrode 2 formed below the encapsulation dam 4, of the width of the electrode finger, has such a value that the propagation loss y of surface acoustic wave due to the encapsulation dam 4 is minimized in relation to a width x that the encapsulation dam 4 has in the propagation direction of the surface acoustic wave.SELECTED DRAWING: Figure 1 【課題】伝搬損失を極小化する弾性表面波センサの製造方法を提供する。【解決手段】弾性表面波を送信、受信又は反射する櫛形電極２と、被測定物である液体を導入される検出領域３と、櫛形電極２と検出領域３との境界近傍の櫛形電極２上（つまり、ダミー電極上）に形成され、被測定物である液体の検出領域３から櫛形電極２への侵入を防止する封止ダム４と、を備え、封止ダム４下に形成される櫛形電極２のうちの、金属薄膜で形成される電極指の幅と金属薄膜が形成されない隣接電極指間の幅との和に対する、電極指の幅の比率であるメタライズ比ｍは、封止ダム４が弾性表面波の伝搬方向に有する幅ｘに対して、封止ダム４による弾性表面波の伝搬損失ｙが極小化されるような値を有することを特徴とする弾性表面波センサＳである。【選択図】図１