An underfilling material for a semiconductor package holding semiconductor elements on a carrier substrate mounted on a circuit board, containing a one pack type thermosetting urethane composition which preferably comprises {HEAD ~ a urethane prepolymer} having {TAIL ~ a terminal isocyanate group}, which is obtained by reacting a polyol with an excessive amount of a polyisocyanate, and a fine powder coated curing agent comprising a curing agent which is in a solid state at room temperature and surface active sites of which are covered with a fine powder 
An underfilling material for a semiconductor package holding semiconductor elements on a carrier substrate mounted on a circuit board , containing a one pack type thermosetting urethane composition which preferably comprises { HEAD ~ a urethane prepolymer } having { TAIL ~ a terminal isocyanate group } , which is obtained by reacting a polyol with an excessive amount of a polyisocyanate , and a fine powder coated curing agent comprising a curing agent which is in a solid state at room temperature and surface active sites of which are covered with a fine powder
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH