This invention relates to thermosetting resin compositions useful for
mounting onto a circuit board semiconductor devices, such as chip size or
chip scale packages ("CSPs"), ball grid arrays ("BGAs"), land grid arrays
("LGAs"), and the like, each of which having a semiconductor chip, such
as large scale integration ("LSI"), on a carrier substrate, as well as
compounds useful in such compositions. The compositions include compounds
having a thermally cleavable linkage, and include an episulfide group
within the compound. The compositions of this invention are reworkable
when subjected to appropriate conditions.