Browse Prior Art Database

304 Lead Surface Mount Rectangular Package

IP.com Disclosure Number: IPCOM000112856D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 4 page(s) / 134K

Publishing Venue

IBM

Related People

Sturcken, K: AUTHOR [+2]

Abstract

Most electronic packaging for military and space applications is done using a standardized rectangular circuit card format known as SEM-E. Almost all components that are assembled to boards using surface mounted technology (SMT) are generically square which results in inefficient use of the area on the circuit board. This inefficiency has been overcome by developing a rectangular package. This package has been built and is now in use.

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304 Lead Surface Mount Rectangular Package

      Most electronic packaging for military and space applications
is done using a standardized rectangular circuit card format known as
SEM-E.  Almost all components that are assembled to boards using
surface mounted technology (SMT) are generically square which results
in inefficient use of the area on the circuit board.  This
inefficiency has been overcome by developing a rectangular package.
This package has been built and is now in use.

      Currently almost all electronic packaging for military and
space applications is done using circuit cards designed to the SEM-E
(Standard Electronic Module, Revision E) standard which specifies
that the circuit card be rectangular (5.20"w x 6.60"l).  Until now,
the components that were mounted onto these circuit cards were
generically square which resulted in inefficient use of the area on
the circuit board.  This became particularly true in recent times as
larger and larger components were used.  This inefficiency posed a
major problem to electronic packaging since high packaging density
was one of the key objectives for military and space applications.

      By developing a rectangular package, the area on a rectangular
SEM-E board can be used very efficiently.  In fact, by properly
designing the 304 surface mount package with the right aspect ratio
(the ratio between package length and width) three of these packages
can be placed along the width of a SEM-E card (5.20" w x 6.60"L...