These processes completely immerse the product being washed, so that the cleaning agent fully contacts every surface of the device. Most immersion applications utilize either Ultrasonic energy or Spray -Under -Immersion (SUI) forces to circulate the fluid and apply mechanical energy to the substrate surface.
Ultrasonic cleaning systems use special transducers to transmit high frequency sound waves into the wash or rinse fluid. Where the waves cross, they form tiny bubbles that grow in volume until they can’t absorb any more energy. Like a balloon bursting, they collapse violently in a process called cavitation. The bubble implosion releases a high velocity stream of fluid into the surrounding area. Research performed years ago linked the use of low frequency, high energy ultrasonic energy to component damage and poor yields, especially on packages that incorporate wire bonds. Today’s more advanced systems use sweeping frequencies and lower watt density (~10 watts/liter) to eliminate the harmonics and make it a safer process. Common frequencies are 40, 80, and 120 KHz. Higher frequency equates to smaller bubble formation, which provides more gentle scrubbing action when they collapse.
Spray-under-immersion systems often use large pumps and multiple banks of nozzles to flood the assembly with rapidly churning fluid movement. Mechanical energy applied to the PCB surface is gentler rather than blasting it like high-pressure spray in air (SIA) or ultrasonics. This process relies on solvency power rather than brute mechanical force to provide cleaning. Therefore the most successful SUI cleaning agents are well matched to the flux residues being removed. .
Best-in-Class cleaning agents designed for ultrasonic and spray-under-immersion systems are single phase (homogenous) engineered fluids with low surface tension.
KYZEN’s Aquanox and Ionox family of cleaning agents are designed specifically to match to the soil(s) being cleaned and cleaning machine design. The best cleaning chemistry choice is often dependent on the machine and soil characteristics.
- Ideally suited for ultrasonic immersion cleaning machines
- Strong match to water soluble and rosin flux types
- Cleans many low residue flux types dependent on wash concentration levels
- Best in Class compatibility with aluminum, copper, tin and lead
- Ideally suited for spray under immersion batch and inline cleaning machines
- Strong match to all flux types, including Pb-free
- Extended bath life for a cost effective process
- Proven compatibility with common process materials used in manufacturing