Patent ID: 9108232
Filing Date: 2015-08-18
Classification: B08B,H01L

Abstract:
1. A megasonic processing apparatus comprising: a first piezoelectric transducer operating in thickness mode and having a fundamental resonant frequency of at least 300 KHz and having a first operating frequency; a second piezoelectric transducer operating in thickness mode and having a fundamental resonant frequency of at least 300 KHz and having a second operating frequency different from the first operating frequency; a rectangular mounting plate upon which the first and second transducers are mounted, wherein the mounting plate has an area available for mounting transducers, wherein each first and second transducer is in the shape of a rectangle having a long side and a short side that is shorter than the long side, wherein the first and second transducers are arranged with the long sides parallel to each other and each transducer extends across one dimension of the mounting plate, wherein transducers cover at least 80% of the area of the mounting plate, wherein at the location of the first transducer the mounting plate has a first thickness and has a fundamental resonant or harmonic frequency substantially equal to the first operating frequency, and wherein at the location of the second transducer the mounting plate has a second thickness different from the first thickness and has a fundamental resonant or harmonic frequency substantially equal to the second operating frequency; a tank adapted to contain fluid and one or more parts to be processed, wherein said mounting plate is operatively coupled to the tank so that the transducers provide vibrations to the tank and its contents; and a generator coupled to the transducers for supplying driving signals at the first and second operating frequencies.