SURFACE-MOUNTED TYPE SURFACE ACOUSTIC WAVE FILTER

摘要

PROBLEM TO BE SOLVED: To stop a resin and a solvent from penetrating the electrode pattern surface of a surface acoustic wave chip and to prevent electrical characteristics from deteriorating. SOLUTION: This surface acoustic wave filter is constituted by electrically connecting the surface acoustic wave chip 1 and a planar ceramic substrate 3 by Au bumps 2 and covering the surface acoustic wave chip 1 with a thin internal cap 6 of 20μm in thickness, before coating the chip 1 with an adhesive resin layer 5. Then when the resin layer 5 is applied from above, penetration of the resin or solvent into the electrode pattern surface of the surface acoustic wave chip 1 can be suppressed and the electrical characteristics can be prevented from deteriorating.