The present invention provides a system and method that mounts integrated
circuit devices onto substrates and a system and method for employing the
method in stacked modules. The contact pads of a packaged integrated
circuit device are substantially exposed. A solder paste that includes
higher temperature solder paste alloy is applied to a substrate or to the
integrated circuit device to be mounted. The integrated circuit device is
positioned to contact the contacts of the substrate. Heat is applied to
create high temperature joints between the contacts of the substrate and
the integrated circuit device resulting in a device-substrate assembly
with high temperature joints. The formed joints are less subject to
re-melting in subsequent processing steps. The method may be employed in
devising stacked module constructions such as those disclosed herein as
preferred embodiments in accordance with the invention. Typically, the
created joints are low in profile.