The present invention discloses techniques that improve the reliability of
a flip packages that uses underfill encapsulation. One embodiment of the
present invention describes a method and apparatus of packaging a flip
chip by relocating the neutral plane of the package substrate away from
its mid-plane. Another embodiment of the present invention describes a
method and apparatus of arranging the layers of a laminate for use in
PBGA packaging that arranges the layers of the laminate according to the
stiffness of each layer. Another embodiment of the present invention
describes a method and apparatus of packaging a flip chip that uses one
or more redundant interconnections at the bottom of the package substrate
where the redundant interconnections are within the shadow of the IC
chip.