Some substrate materials are inherent particle generators and may never be cleaned to the point of there being no particles present. With these materials, particles are a way of life and can not be avoided. This, of course, makes cleanliness testing using particle analysis a difficult if not impossible task. The difficulty is exacerbated by … Continued
Many cleaning specifications call for “Spot Free Drying.” I have always taken this to mean that there should be no visible water (or other) spots on the parts once they exit the cleaning process. The offending spots are usually created when water evaporates leaving behind a solid residue. The resulting residues or spots are cosmetically … Continued
There are two fundamental transducer designs used for power ultrasonic applications today, magnetostrictive and piezoelectric. Piezoelectric transducers utilize the piezoelectric property of a material to convert electrical energy directly into mechanical energy. Magnetostrictive transducers utilize the magnetostrictive property of a material to convert the energy in a magnetic field into mechanical energy. The magnetic field … Continued
Liquid-borne acoustic energy in the frequency range between 350kHz and up to about 5MHz is finding growing usefulness in a number of cleaning applications which require processing of extremely delicate parts and assemblies to remove particles ranging from a few microns down to a fraction of a micron in size. This “megasonic” energy varies from … Continued
Abstract A presentation describing the theory of ultrasonics and how ultrasonic technology is applied to precision cleaning. This presentation will explore the importance and application of ultrasonics in precision cleaning along with explanations of ultrasonic cleaning equipment and its application. Process parameters for ultrasonic cleaning will be discussed along with procedures for proper operation of … Continued
The various ultrasonic parameters, or degrees of freedom, available to the process engineer define what the ultimate limits are for the cleaning process. The traditional degrees of freedom available in an ultrasonic cleaning system have included modulation of a single center frequency (sweep), variable duty cycle, and amplitude control at a single frequency. All of … Continued
There are many ways to alter the characteristics of ultrasonic waves in a liquid contained in a tank. The ultrasonic waves can be frequency modulated (FM) by varying the output frequency of the ultrasonic generator. The ultrasonic waves can be amplitude modulated (AM) by changing the amplitude of the generator output and/or by tailoring the … Continued