Cleaning Bath Monitoring

Permanent contamination enters the cleaning and rinsing bath through the cleaning of electronic assemblies. In addition to the contamination, there are also process-dependent influences, such as extraction, evaporation or the spread of cleaner into the rinsing water which can adversely affect the end result.

Regular wash tank monitoring is necessary to ensure consistent results in cleaning processes of electronic assemblies or power electronics. There are manual and automatic methods available.

Three important process parameters can provide information about the quality of the cleaning or rinsing bath:

• pH-value
• Conductivity measuring
• Concentration of the cleaning chemistry

The concentration is important. To achieve the optimum performance of aqueous cleaners, the recommended application concentration must be kept constant within a defined range.
For this purpose, two different kinds of measurement methods are available:

1. Manual: Rapid chemical tests based on an acid–base titration (e.g. Easy Bath Control Kit) or phase separation method (e.g. ZESTRON Bath Analyzer test kits)
2. Automatic: Online and real-time measurement systems (ZESTRON EYE), without or with an automatic dosing unit (ZESTRON EYE CM) or mobile tool to monitor the cleaning agent concentration of several machines (ZESTRON EYE Mobile)

Advantages of bath monitoring:

• Consistent cleaning process due to a constant quality level of the cleaning bath
• Cost reduction by avoiding premature bath changes
• Preventing poor cleaning results due to delayed media changes
• Documentation of the cleaner concentration with a process traceability option (e.g. for ISO 9001 – 2015)