Method of holding a component using an anhydride fluxing agent

A method for attaching an integrated circuit component comprising a plurality of solder bumps to a substrate comprising a plurality of bond pads, the method comprising:

• dispensing a solution comprising a fluxing agent composed of an anhydride compound and dissolved in a vaporizable vehicle onto the substrate including the bond pads;
• vaporizing the vehicle to form a tacky layer on the bond pads;
• superposing an integrated circuit component onto the substrate such that each of said solder bump rests against one of the bond pads and is held by the tacky layer, and such that a gap is formed between the integrated circuit component and the substrate;
• heating to bond the solder bumps to the bond pads and to vaporize the anhydride compound;
• and
• filling the gap with a polymeric encapsulant.

A method for attaching an integrated circuit component comprising a plurality of solder bumps to a substrate comprising a plurality of bond pads, the method comprising:

• dispensing a solution composed of an anhydride compound dissolved in vaporizable alcohol onto the substrate such that the solution is applied to the bond pads;
• vaporizing the alcohol to form a tacky anhydride layer on the bond pads;
• superposing the integrated circuit component onto the substrate such that each of said solder bumps rests against one of the bond pads and is held by the tacky anhydride layer, and such that a gap is formed between the integrated circuit component and the substrate;
• heating to bond the solder bumps to the bond pads and to vaporize the tacky anhydride layer;
• and
• filling the gap with an epoxy-base resinous encapsulant that cures at a curing temperature and includes epoxy end groups and hydroxyl end groups that react with residual anhydride at the curing temperature.