BP 256 solder joint encapsulant is for BGA, CSP, flip-chip, PoP, and other ball bumping applications. Is said to create a solder joint bond five to 10 times stronger than a conventional solder joint, enhancing reliability and eliminating cracking. For use in lead-free, SnPb and SnBi processes. Reworkable.
Yincae, http://www.yincae.com/technical-information.html