An underfill material, such as a no flow underfill material, containing an anhydride
adduct of a rosin compound is disclosed. In one aspect, the anhydride adduct of
a rosin compound contains an organic rosin acid moiety and a substitute moiety
for a hydroxyl group of a carboxylic acid attached at an acyl group of the organic
rosin acid moiety. In another aspect, the anhydride adduct of the rosin compound
contains a plurality of linked organic rosin acid moieties. Methods of using the
underfill materials and packages formed by curing the underfill materials are also disclosed.