Saw Devices Substrate, Non-destructive Testing Applications

Piezoelectric material for SAW devices is the decision factor affecting SAW device characteristic. SAW transmission speed is one of the most important indexes in all characteristic parameters about piezoelectric wafer, directly deciding resonator frequency of the device. Therefore, knowing about SAW transmission speed and it's consistency in batches of SAW producing looks like very vital.The update report about testing surface acoustic speed shows that the method of test is either destroyed checkout or complicated process in and out aboard .So it can't be used as a conventional test in batches of producing.The design testing piezoelectric material surface acoustic during the experiment process in the paper has several merits: convenience, efficiency, no loss, fastness. And they can be realized. The design applies material piezoelectric response and anti-piezoelectric response to stimulus and receive SAW, and apply the method of testing resonator frequency to calculate SAW tested speed, simultaneously contrast the actual test result about different material to typical value in the paper. Some problems are solved in applying to produce.1) To test piezoelectric wafer's SAW transmission speed .Use sorts of wafers having different speed during produce, controlling frequency consistency.2) To make the criteria and method with no loss and fasting resolution for received wafer and mixed-up wafer, apply to produce.3) To take advantage of the instrument having no loss and fast speed, analyze and test wafer dwelled with different methods, analyze the rejected function caused by parasitical response about different body acoustic wave and the effect produced by kinds of characteristics about SAW device. We make a rule that different kinds of characteristic devices have wafer matched material, and apply it to produce.At the same time, according to the decision drawn by experiment process, chose the representative product from middle-frequency device and high-frequency device to do the experiment during practice production, then do batches of production, cheek the consistency. The result proved that both acceptance ratio tested by probe and frequency...