1996 Electronics Industry Environmental Roadmap - Civil and ...

Appendix A
IPC Conventional Interconnect Structures
Conventional and threshold printed boards include all one-sided, twosided,
and multi-layer boards that are manufactured using FR-4,
polyimide, cyanate ester, or other epoxy-based resins.
Needs in this area generally involve improvement of photo tools used
to produce printed circuit boards, processes for fabricating finer and
finer conductors on inner layers, processes enabling finer conductor
widths (etch), improved mechanical hole-drilling as well as alternative
hole formation techniques such as laser ablation, photo image and
plasma techniques, (imaging outer layer?), improved copper plating
processes, improvements in solder mask, more stringent final
fabrication requirements, improved electrical evaluation and testing.
Highest priority in the short is smaller, less expensive holes.
Subsequent priorities focus on electrical test capability, better laminate,
recycling, waste reduction, and direct imaging. Evolution of
equipment capabilities is also important.
Emerging Interconnect Structures
Pressures toward miniaturization, portability, and, in general, the size
and weight reduction of electronic products requires smaller
assemblies and are driving toward increased use of direct placements
of uncased, bare chips on the interconnecting structures. Such
assembly technology is called direct chip-attach.
This approach is generally incorporated in multi-chip modules, of the
type MCM-L, MCM-C, and MCM-D, or variations of these three
types, as well as rigid-flex, memory modules (2D and 3D), single inline
memory modules and PCMCIA types.
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