TY  - JOUR
AB  - Packages for multichip modules in
military airborne applications must hava some fundamental characteristics: high
thermal conductivity, low density, good mechanical properties and a coefficient of thermal
expansion nearly equal to that of the microelectronic substrate installed in the package. In
many cases, the substrate is alumina with a CTE of 6.5 ppm/°C. Materials such as
aluminium, titanium or Kovar fulfil only part of the above requirements. This is critical when
large packages are used, such as in electronic warfare systems where modules include
wideband RF circuits with large alumina substrates next to dense digital circuits. The solution
is then aluminium/ silicon carbide (Al/SiC). The
aim of the paper is to present the development and qualification of large packages combining
both RF and digital circuitry. The size taken into account in the study is 220 × 220
mm: it covers most of the electronic needs in terms of surface. Various aspects have
been analysed from the perspective of the package manufacturer and the end‐user. The interest of Al/SiC is shown by a thermal analysis of a
conduction cooled module with different core materials: the reduction in temperature
gradient, which for some components reaches 20° C, has a strong effect on the module
reliability. The different technological choices, for a first type of packages, are
described: an Al/SiC baseplate with an iron‐nickel alloy for the ring and
the lid, brazed feedthroughs (within the Al/SiC baseplate) and connectors,
surface treatment, ring brazing material, lid welding technique. A second type of packages is
also presented: the main difference lies in the interconnections. RF ceramic
(HTCC) inserts are introduced in the ring frame. Various RF measurements show
the interest of the different package technologies, especially the ceramic inserts with very good
results up to 20 GHz.
VL  - 13
IS  - 1
SN  - 1356-5362
DO  - 10.1108/13565369610800151
UR  - https://doi.org/10.1108/13565369610800151
AU  - Lefeuvre A.
AU  - Caplot M.
AU  - Stranieri C.
AU  - Massiot P.
PY  - 1996
Y1  - 1996/01/01
TI  - Large AI/SiC Baseplate Packages for Digital and Microwave
Applications
T2  - Microelectronics International
PB  - MCB UP Ltd
SP  - 26
EP  - 30
Y2  - 2024/04/23
ER  -