Browse Prior Art Database

Corrugated Cover For Large Area Hybrids/MCM

IP.com Disclosure Number: IPCOM000113477D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Glovatsky, AZ: AUTHOR [+5]

Abstract

Large volume hermetic enclosures are rapidly emerging as the package of choice for complex hybrid and multichip module applications. Many use standard seam welding techniques to produce the seal between the enclosure base and the cover. This process mandates the use of thin (0.005") Iron-Nickel (Fe/Ni) alloy plates as covers in order to achieve a successful hermetic seal.

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Corrugated Cover For Large Area Hybrids/MCM

      Large volume hermetic enclosures are rapidly emerging as the
package of choice for complex hybrid and multichip module
applications.  Many use standard seam welding techniques to produce
the seal between the enclosure base and the cover.  This process
mandates the use of thin (0.005") Iron-Nickel (Fe/Ni) alloy plates as
covers in order to achieve a successful hermetic seal.

      As these hermetic enclosures increase in size for more complex
module designs, the thin cover presents a correspondingly more
serious problem.  Since the packages are sealed under ambient
conditions, the internal pressure of the module is initially at 1
atmosphere.  Variations in temperature and altitude within the
application environment, including the vacuum of space, result in a
pressure differential which in turn causes the thin cover to bow
inward or outward depending on the conditions.  This can result in
contact between the cover and internal components or adjacent modules
outside the package.  Both situations are typically unacceptable.
Computer-aided structural modeling indicates that to produce a module
which will withstand the pressure differential without bowing, the
cover must be significantly thicker (i.e., > 10X), and as such, would
preclude the use of the reliable and cost-effective seam weld
process.

      A solution to this problem is a design for a corrugated cover
as shown in the cross section in the Figure. ...