about 60 percent by weight desirably within the range of about 15 to about 35 percent by weight as the thermal initiator that liberates a cationic catalyst many different materials can be used depending upon the temperature at which cure is desired to occur for instance to achieve cure at a temperature of about 120 u00b0 c an appropriate thermal initiator is ammonium antimonite for a temperature in the about 150 u00b0 c to about 180 u00b0 c range a variety of other materials may be used the cationic catalyst should be present in an amount with the range of about 0 05 percent by weight to about 10 percent by weight desirably about 0 1 percent by weight to about 5 percent by weight such as about 1 percent by weight of the total composition in addition adhesion promoters such as the silanes glycidyl trimethoxysilane commercially available from osi under the trade designation a 187 or gamma amino propyl triethoxysilane commercially available from osi under the trade designation a 1100 may be used conventional additives may also be used in the compositions of the present invention to achieve certain desired physical properties of the composition the cured reaction product or both the thermosetting resin compositions according to the present invention are capable of penetrating into the space between the circuit board and the semiconductor device these inventive compositions also demonstrate a reduced viscosity at least under elevated temperature conditions and thus are capable of penetrating into that space it is desirable to prepare the thermosetting resin composition by selecting.