What are the differences between these 2 fluxes?

[jamesmith134]

Hello!

I wanted to get a flux paste but found these 2 types: RMA-223 and RMA-218.
What is the difference between them? each of them has a specific purpose?

Thank you 

[mcinque]

RMA-223: not properly a mere flux, "pre-alloyed solder powders and mildly activated resin paste flux" (from http://www.amtechinc.com/pastes.html)

RMA-218: should be a no-clean, high viscosity flux used in reballing

[nanofrog]

The numbers aren't consistent between manufacturers. 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). What you also need to watch for with paste products, is whether or not it's just flux, or has metal in it (solder paste).

Based on what you've indicated, both are Rosin Mildly Activated types. That's all that can be determined without a datasheet or trying it out (ultimately what you'd need to do to test performance).

Take a look at the following links:
Kingbo's page (RMA-218)
Amtech's Datasheet for their RMA-223 (.pdf, this particular data sheet = solder paste, not just flux).
The Tacky Flux version datasheet (here, .pdf), is just flux.