ELECTROMAGNETIC ACOUSTIC TRANSDUCER

摘要

PURPOSE: To provide an electromagnetic acoustic transducer whose best characteristic is realized by using heat application by reflow soldering without receiving adverse effect of the heating. CONSTITUTION: The electromagnetic acoustic transducer is provided with a magnetic drive section formed by winding a coil 24 to a magnetic core 22 erected upright to a base 20 and the height L3 of the coil 24 in the case of manufacture is set lower by a height L2 set higher by thermal expansion of the coil 24 at reflow soldering (setting of coil length to be L1). Or a projected length H1 of a magnetic core projected from the coil 24 is set higher by a height H2 set higher by thermal expansion of reflow soldering (setting of H3 as projected length).