Ultrasonic cleaning with MEGASONIC Sweeping® generators
Megasonic stands for technology to delete particles in the micro and/or nano range of very sensitive micro structures. The MEGASONIC sweeping® generators are equipped with a sweep function to achieve a homogeneous transfer of Megasonic energy in to the bath resulting in as short as possible contact times. Hot spots will be avoided so that damages on critical parts will not occur and there is a considerable reduction of shadow working. Typical applications are found in the LIGA technology, in the production of semiconductor wafers, solar cells, opto-electronics, LCD’s , substrates and MEMS (Micro Electro Mechanical Systems).
The available frequencies are 470 kHz and 1 MHz Depending on the chosen frequency there are modular generators available with a power off 200W and up to 2 kW. The Megasonic elements can be mounted under a bath of Teflon, Quartzglas or a high-quality finished stainless steel bath. It is also possible to mount the Piezo elements in a liquid-tight housing, also called Array.
Megasonic with sweep
A sweep with a certain speed ensures that each Piezo could be tuned on his optimal natural resonance frequency. The produced Megasonic energy is homogeneous distributed in the entire bath. The cleaning process will be optimized resulting in a faster operation with a greater capacity. The cleaning time could be shortened resulting in a possible adverse impact on sensitive components, or on the product properties should be avoided.
Megasonic without sweep
Without sweep and a Piezo with a frequency that is closest to the Megasonic generator frequency will cause a standing wave and results in a fountain effect. The energy caused by the rapid increase in hotspots that arises may damage sensitive parts. The electrical energy is not evenly distributed over the existing Piezo elements such that for each standing wave the remaining Piezo’s gets another current and the process will be so insufficient disrupted that the results are not reproducible.