In general, fabrication schedules for thick film MIBs are
similar to those for polymer-glass MLBs. Complexity is the dominant factor in
the determination of a schedule. When schedule is of prime importance and
production facilities are accelerated to their ultimate production rates, MLBs
can be fabricated and delivered in a shorter time span. Introduction of the
MIB approach requires a concerted effort among the design, manufacturing, and
product assurance operations. Realistic schedules must be established,
otherwise a poorly executed introduction of new materials into manufacturing
will result in significant cost, schedule, and reliability problems.
Both copper and noble metal thick film MIBs may be procured from
a number of competent manufacturers who can provide delivery quotes. However,
manufacturers with experience in fabricating thick film hybrids (small
substrates with only one or two noble metal or copper conductor layers) may
wish to expand that capability into a complex MIB facility. If the MIBs are to
be fabricated "in- house" in an existing hybrid operation, in-house capability
and its impact on schedule must be considered carefully.
Figure 3-10 indicates the steps and the length of time that must
be planned to convert an existing thick film hybrid facility into a complex
MIB facility, including a change in conductor metal between copper and noble
metal. Ten to twenty-six months should be allowed for such a conversion,
depending upon the level of previous experience with the particular material
system and whether or not a furnace must be procured.