| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide no-clean flux generating solventless thermoplastic residue and forming thermosetting resin by the thermoplastic residue reacting with an underfill component. <P>SOLUTION: The no-clean flux includes dicarboxylic acid as a flux activator, an epoxy prepolymer having an average function group number of around 2.0 as a resin component, and a solvent with its boiling point equal to or lower than 260°C as a viscosity modifier. The no-clean flux eliminates an oxide film of solder during reflow, and forms a thermoplastic epoxy cured material which becomes a liquid form when coating the underfill at glass transition temperature of 100°C or lower. Regarding the solvent as a viscosity modifier, almost the total amount volatilizes during the reflow. After the reflow, when coating the underfill without cleaning, the cured material is compatibilized with the underfill and reacts with the curing agent contained in the underfill, which can form a three-dimensional cross-linked structure together with the underfill. <P>COPYRIGHT: (C)2013,JPO&INPIT |
