Patent ID: 6929014

Claim:
A method of treating a workpiece having a pair of opposed, planar surfaces with ultrasonic energy, comprising the steps of: (a) providing an apparatus comprising: (i) a chamber having an interior space containing therein a liquid, said chamber comprising a bottom wall and a first pair of opposing, longitudinally extending sidewalls connected by a second pair of opposing, transversely extending sidewalls, and a movable partition within said interior space, said movable partition extending transversely at least partway between said first pair of opposing, longitudinally extending sidewalls for adjustably partitioning said interior space into a first sub-space including a planar transducing surface and a second sub-space including said second one of said second pair of opposing, transversely extending sidewalls, each of said first and second sub-spaces extending for a desired, adjustable length alone said first pair of longitudinally extending sidewalls, said movable partition being comprised of a material which is partially reflective and partially transmissive of ultrasonic energy; (ii) an ultrasonic wave energy applying means for supplying ultrasonic energy to said liquid in said chamber, said ultrasonic wave energy applying means including said planar transducing surface forming at least a portion of a first one of said second pair of opposing, transversely extending sidewalls; and (iii) a workpiece mounting means positioned within said interior space of said chamber for mounting therein a workpiece, wherein said workpiece mounting means is positioned in either said first sub-space or said second sub-space at a spacing from said transducing surface which provides said pair workpiece surfaces with a desired amount of ultrasonic power; (b) positioning within said interior space a said workpiece mounting means having a said workpiece, such that each of said pair of workpiece surfaces is in contact with said liquid; and (c) applying ultrasonic energy from said planar transducing surface to said liquid for simultaneous treatment of each of said pair of workpiece surfaces.