ROSE testing for no-clean flux soldering assemblies

Subscribe to Thread

How does no-clean flux residues on a PCB assembly impact the... - Aug 19, 2019 by yb

ROSE testing a post-reflow assembly which has been reflowed ... - Aug 19, 2019 by Michael

Hello Mike, Thank you for your response. This information is... - Aug 19, 2019 by yb

#83312

ROSE testing for no-clean flux soldering assemblies | 19 August, 2019

How does no-clean flux residues on a PCB assembly impact the ROSE testing? Does no-clean flux residues on the PCBA dissolve in solution of ROSE tester and increase ionic contaminants level in terms of NaCl per surface area? Is ROSE tester solution (assuming about 75% DI water and 25% IPA) a strong cleaning agent to remove no-clean flux residues from the board surface? Is that possible? or the ROSE tester solution would not have any impact on the ROSE testing outcome as far as no-clean flux residues are concerned.

Thank you for your response in advance.

reply »

Michael

#83315

ROSE testing for no-clean flux soldering assemblies | 19 August, 2019

ROSE testing a post-reflow assembly which has been reflowed using no-clean flux may not yield information that is helpful. No-clean flux technology works by encapsulating the flux's activators and other chemical constitutes that would be harmful if left un-encapsulated on the assembly. The ROSE tester will measure both encapsulated residues and un-encapsulated residues. It cannot discern the difference. The ROSE tester will provide a bulk (totalized) value. It is impossible to tell how much of the residue detected was harmful (un-encapsulated) or non-harmful (encapsulated).

If one desires to compare one no-clean brand from another by comparing the total residues after reflow, a ROSE tester would be beneficial. It is not possible to extrapolate that information into likelihood of ECM failures as it wouldn't know how much of the totalized residue volume would have been exposed verses encapsulated.

I hope this information is helpful.

Mike Konrad Aqueous Technologies

konrad@aqueoustech.com

reply »