| 摘要 |
PURPOSE:To secure more perfect conductive performance on the back of the substrate by forming the metal film on the back of the substrate on the surface of which the inter-digital electrode is formed, and thus to increase the shielding effect as well as to enhance the side lobe of the frequency property. CONSTITUTION:Metal film (f) such as Al, Cu or the like is formed through the vacuum evaporation, spattering or plating means on the back of substrate (a), i.e., the adhesion side of the substrate to package case (b), and then attached to case (b) via conductive adhesive (e). This method features more perfect shielding effect in comparison with the conventional method in that the attachment is carried out only through adhesive (e). Then PZT of 0.5mm thick is used for substrate (a), and five pieces of 0.2mm grooves are provided (b) on the back of the inter-digital electrode. After this, the Cu film of 5000Angstrom is formed through the vacuum evaporation on the surfaces of the grooves and then adhered to case (b) via adhesive (b). Thus, the side lobe of frequency property 50 can be improved about 10dB in comparion with the conventionl one. |
