Mar 24, 2020 · Rosin activated (RA) flux combines rosin, solvent, and aggressive activators. Activity is higher than RMA for use on oxidized surfaces. RA flux is corrosive so sensitive assemblies must be cleaned as soon as possible with a compatible solvent or risk damage to electrically conductive performance.

Apr 17, 2019 · Two common types of rosin flux are Rosin Activated (RA) and Rosin Mildly Activated (RMA). RA is the most acidic one. The residues from rosin flux are mildy corrosive and should be removed after soldering to avoid eventual failure of the board. RMA solder has been formulated such that the cleaning, while recommended, can be omitted.

Jan 9, 2015 · One uses Rosin Activated flux (RA) and one uses a "No-Clean" flux. The No-clean one, however, uses the 63/37 ratio rather than 60/40 as the RA one does. Is it right to assume that the rosin flux will be better at cleaning oxidation …

Apr 7, 2014 · What does tend to be more consistent, is the letters R, RMA, and RA that describe the rosin & activation level (R = Rosin, RMA = Rosin Mildly Activated, and RA = Rosin Activated; weakest to strongest cleaning action).

Apr 22, 2014 · There are three types of rosin flux — rosin (R), rosin mildly activated (RMA), and rosin activated (RA) — each of which have a different level of activators, the agents enabling the flux to deoxidize and clean.

The choice of the proper flux formula is based on the soldering application, desired rosin percentage, type of solvent and the activity level required. Rosin Mildly Activated (RMA) Fluxes

Apr 29, 2010 · Rosin activated (RA) flux consists of rosin, solvent, and aggressive activators. RA flux has similar and higher activity than RMA for moderately and highly oxidized surfaces.

Rosin Activated (RA) RA flux consists of rosin, solvent, and aggressive activators. RA flux has similar and higher activity than RMA for moderately and highly oxidized surfaces. IPC classification is usually ROM0, ROM1, ROH0, or ROH1. In the absence of testing to prove otherwise, RA flux residue is assumed to be corrosive.

RA flux contains activated rosin, and is the most active flux. It's probably more suitable for hobbyists as it'll be easier to get good joints. Use 99% isopropyl alcohol for removing it.

Rosin mildly activated (RMA) flux consists of rosin, solvent, and a small amount of activator. Most RMA flux is fairly low in activity and best suited to easily solderable surfaces.