ULTRASONIC WAVE TRANSDUCER

摘要

PURPOSE:To obtain a material for a matching layer having an optimum specific acoustic impedance by decreasing the density of a composite mixing member through the heating and thermal expansion in advance before minute hollow spheres having the performance of thermal expansion are mixed to a base member. CONSTITUTION:The matching layer 9 made of a composite material is provided to the acoustic wave radiating plane 8 of a piezoelectric ceramic oscillator or magnetostriction oscillator 7. The layer 9 is obtained by using a silicone resin as a base member, mixing a thermal expansion minute hollow sphere, e.g., plastic minute hollow sphere having thermal expansion gas thereto so as to form a composite member, heating the composite member so as to expand the thermal expansion balloon and curing the composite member. The specific acoustic impedance smaller than the specific acoustic impedance of the synthetic resin base member of a single body is obtained by decreasing the density of the composite member in this way so as to bring the impedance very close to the specific acoustic impedance demanded fo the matching material.