PRE-APPLIED UNDERFILL

摘要

PROBLEM TO BE SOLVED: To provide a dry film structure useful to form a pre-applied underfill in electrical assemblies.SOLUTION: Underfill structures useful as pre-applied underfill materials comprise a polymer layer including a first filled polymer region 20 having a first viscosity and a second filled polymer region 30 having a second viscosity. The first viscosity is less than the second viscosity. Electronic assemblies comprising a chip or die and a substrate are formed using such multi-layer structured pre-applied underfill.SELECTED DRAWING: Figure 1A