SURFACE ACOUSTIC WAVE DEVICE

摘要

PROBLEM TO BE SOLVED: To drastically reduce the cost of a SAW filter by enhancing the judgment accuracy of acceptance very much at a wafer stage by enabling a high frequency probe to measure/select non-defective of the frequency characteristic of the SAW filter formed on a wafer while preventing comb-shaped electrode fingers from being subjected to discharge breakdown by pyroelectric effect due to rapid temperature fluctuation in a SAW filter producing process. SOLUTION: The relation between the total area of the formation region of a wire electrode and comb-shaped electrodes connected to the wire electrode and the inter-electrode finger distance of an IDT electrode meets the following expression. S <=1.49×105×√(Lidt-0.4) (however, S: total area (μm2) of wire electrode and comb-shaped electrode connected to wire electrode, and Lidt: inter-electrode finger distance (μm) of IDT electrode)).