I have a rhetorical question. The bromine compounds in FR4 are bound by covalent bonds into the epoxy structure and are theoretically harmless, at least until they reach decomposition temperature. Filler materials may have sulfur bound into their molecules either covalently or ionically, but always another relatively small molecule which is not integral in the epoxy structure. Surely, these two cases cannot be considered as similar??? Brian On 07.05.2013 15:46, Victor Hernandez wrote: > Fellow TechNetters: > > We are doing some preliminary investigation of solder mask and have found out that it contains low levels of sulfur. Not sure what sulfur constituents. Is This a typical finding of sulfur? > > Victor, > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________