Browse Prior Art Database

Positioning Techniques for Odd-Shaped Semiconductor Heat Sinks

IP.com Disclosure Number: IPCOM000100716D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 4 page(s) / 126K

Publishing Venue

IBM

Related People

Kelly, HL: AUTHOR

Abstract

Disclosed is a procedure and associated hardware to locate semiconductor heat sinks of varying, odd shapes in relation to the substrates they will be joined to. The locating hardware is used either during or immediately prior to the encapsulation process. The uniqueness of this invention is in the way the described hardware may be retracted and removed in multiple steps, some vertically and some horizontally, to allow for non-uniformity or protrusions in the heat sink design.

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Positioning Techniques for Odd-Shaped Semiconductor Heat Sinks

       Disclosed is a procedure and associated hardware to
locate semiconductor heat sinks of varying, odd shapes in relation to
the substrates they will be joined to.  The locating hardware is used
either during or immediately prior to the encapsulation process.  The
uniqueness of this invention is in the way the described hardware may
be retracted and removed in multiple steps, some vertically and some
horizontally, to allow for non-uniformity or protrusions in the heat
sink design.

      This technique is utilized to locate heat sinks that have a
shape factor which inhibits straight-up removal of a locating frame,
when positioning 4 heat sinks on top of 4 substrates in a "4-up"
capping fixture.  This situation is illustrated by the cap-heat sink
assemblies seen in Figs. 1 and 2.  Both of these assemblies are
comprised of a ceramic cap, which must be located precisely in
relation to the substrate, and a larger, imprecise metal heat sink
which is attached on top.  Any hardware which is used to position the
ceramic cap must be removed after the fixture is clamped, but the
metal heat sink prohibits vertical removal unless horizontally
sliding jaws are incorporated.  Such jaws would add complexity and
additional parts, and take longer to use. There are currently four
different MLC module cap/heat sink configurations at our facility
which experience the problem described, two are nominally 44 mm
square, like the example in Fig. 2, and two are for 28 mm product,
like the assembly shown in Fig. 1.  All of the 4 shape factors were
handled by the hardware disclosed in this invention and described
below.

      As shown in Fig. 3, a unique locating system was designed to
handle the problem caps discussed.  A large outer ring 1...