Process Control


Indication of carboxylic-based flux residues on PCB assemblies

The ZESTRON® Flux Test indicates carboxylic-based flux activators through a color reaction. The test is an important supplement to the ionic contamination measurement, as non-visible flux residues can be easily detected. 

Additionally, the ZESTRON® Flux Test helps to visualize the local distribution of contamination with flux residues which in turn ensures an improved component reliability assessment. Residues based on halogenated activators, however, cannot be detected with the ZESTRON® Flux Test Kit.

Advantages of the ZESTRON Flux Test:

  • The distribution of local contamination helps to determine the climatic reliability of electronic assemblies
  • Quick and easy test method. No extensive training required
  • No special test equipment needed
  • No additional floor space requirements
  • No capital investment costs
  • Can be used throughout the facility
  • Low cost per tested part

Simple Test procedure in a few steps:

Rinse and dry
flux residues, flux activators


  • Detection of flux activators on pcb assemblies
  • On-site sampling inspection during production