| 摘要 |
PURPOSE:To make the device smaller in size and also save the manufacturing cost, by forming electrodes of the elastic surface wave device which is used for a television channel selection equipment, so as to become from a thin pattern to a thick pattern in order by use of patterns whose film thickness is different, by means of the photolithographic technique. CONSTITUTION:On the piezoelectric substrate 1 are provided the UHF track 10a consisting of an input electrode 2a for propagating an elastic surface wave of UHF band, a grating electrode 5a and output electrodes 3a, 4a, the VHF (H) track 10b and the VHF (L) track 10c, having the same constitution as said track 10a. The thickness of a metallic pattern (electrode) of the UHF band 10a is 0.3mum, and that of a metallic pattern of the VHF bands 10b, 10c is 0.6mum by means of vapor deposition. At the time of this vapor deposition, at first, a film of 0.3mum is vapor- deposited, the UHF band pattern and the whole surface position of VHF band are treated to form a photoresist, and subsequently the UHF band pattern is formed by the photolithographic technique. After that, the UHF band pattern is treated to form a photoresist and after it has been vapor-deposited until its thickness becomes 0.6mum, the VHF band pattern is formed in the same way. |
