Some technological and encapsulation issues of SAWS manufactured on langasite

This paper presents some aspects encountered in fabrication of surface acoustic wave (SAW) manufactured on langasite substrate. Results obtained after the first electrical test didn't correspond to our expectations, although all devices passed through on optical inspection. It followed the de-capsulation of defective devices and the searching for failure causes. We detected several such mechanisms and after fixing them, we encapsulated and tested again the devices. Now, all devices were functioning properly. Comparative results of electrical test (before and after fixing the failure) are given.