No Clean Flux Problems

Tacky Substance Under Zero Clearance Parts

"We are having failures with large, flush sitting components. When we remove the parts we find a tacky substance. Is this residue common?"

Source: Circuit Net

Problem with 'No Clean' Solder Flux Residue

Problem with 'No Clean' Solder Flux Residue:

Example:

“Just to be clear, no-clean does not mean that it does not have to be cleaned. It simply means that it leaves behind less residue than higher solids content fluxes. The residue is most likely lightly corrosive. The white residue is most likely unencapsulated metal salts. Conformal coating over the top of the residue is not recommend.

The potential for electro-migration is increased when flux (no-clean or otherwise) is allowed to stay on the assembly. It only takes three key ingredients to grow dendrites (metal crystals) on a board. These three ingredients are voltage, conductive / corrosive material (flux) and moisture (humidity). The flux residue forms a conductive path connecting an anode to a cathode. The results are either electrical leakage (a temporary problem) or dendrite growth (a permanent problem).”

Mike Konrad
Aqueous Technologies

Source: Experts opinions: http://www.circuitnet.com/experts/56589.html


'via Blog this'

Cirris Systems - Flux Can Cause Opens or High Resistance

Cirris Systems - Flux Can Cause Opens or High Resistance:

'via Blog this'