Sk. Bhattacharya et al., Fabrication of a fully integrated passive module for filter application using MCM-D compatible processes, J MAT S-M E, 11(6), 2000, pp. 455-460
Integral passive is an emerging technology which is currently perceived as
a possible alternative to the discrete passive technology in fulfilling the
next generation packaging needs. Although discrete surface mount passive c
omponents (resistors, capacitors, and inductors) have been well characteriz
ed, the development of integral passive components suitable for co-integrat
ion on the board level is relatively recent. Since in some applications the
number of passive components can exceed the number and the area of IC chip
s on a circuit board or in a package, such integration of passive component
s would be necessary to substantially eliminate part count and reduce devic
e area. To address these issues, integration technology for passive element
s in the same manner as for transistors is necessary. In addition, the fabr
ication sequence of all integral passive components should be mutually comp
atible for co-integration on the same substrate. In this paper, materials a
nd fabrication issues for passive elements such as resistors (R), capacitor
s (C), and inductors (L) and the feasibility of integration of these fabric
ated passive components on glass substrates have been addressed. An active
filter circuit has been selected for a case study for R, L, and C co-integr
ation. This passive module contains eleven resistors, four capacitors, and
four inductors, and is fabricated using MCM-D (multichip module-deposited)
compatible processes. A variety of materials appropriate for fabrication of
integral passives in a mutually compatible fashion were investigated, incl
uding chromium and nickel-chromium resistors, composites of high dielectric
constant materials in epoxies for capacitor dielectrics, and composites of
magnetic ferrite particles in polyimides for inductor core and shielding.
The fabricated devices showed good agreement between the design values and
the corresponding measured values. It is anticipated that some of these mat
erials and fabrication processes can be implemented for the MCM-L (multichi
p module-laminate) compatible packaging. (C) 2000 Kluwer Academic Publisher
s.