Browse Prior Art Database

Reclamation of Strip and Dip Butyl Coated Core Planes/Arrays

IP.com Disclosure Number: IPCOM000089172D
Original Publication Date: 1977-Sep-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Anschel, M: AUTHOR

Abstract

A process for the reclamation of strip and dip ferrite memory planes and/or arrays is presented.

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This is the abbreviated version, containing approximately 56% of the total text.

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Reclamation of Strip and Dip Butyl Coated Core Planes/Arrays

A process for the reclamation of strip and dip ferrite memory planes and/or arrays is presented.

Chemical and electrical investigation of polymer-coated core failures indicate the following:

a) The failure to insure the removal of all of the hardened EPON* core coating prior to butyl encapsulation is a cause for external core stress each time the BSM is power-cycled between room ambient and machine operating temperatures.

b) Aged EPON undergoes substantial loss of AROCLOR** (plasticizer) and the solvents xylene, MIBK, and methylene chloride, thus, reducing EPON's ability to dampen the magnetostrictive oscillations of ferrite cores. The loss of coating constituents during aging leaves a hard, brittle and glassy material which is characterized by a relatively high glass transition temperature.

c) Hardened thick coatings of EPON result in constriction and external stress of ferrite cores.

Memory arrays containing EPON/butyl coated cores (S&D) can be made functional by subjecting the arrays to a softening formulation (composed of a solvent and plasticizer) followed by a sealant formulation treatment. Thus reclamation is achieved by:

1) reflowing and redistributing core coating more uniformly (overcoming uneven stress distributions)

2) lowering Tg of EPON

3) providing a barrier film to prevent or minimize plasticizer/ solvent losses, as well as incorporating detackifying properties to butyl core coating.

Soft and Seal Process: Softening Formulation - 85% monochlorobenzene 15% N-methyl-2-pyrrolidone.

Seal Formulation - 0.1% decafluoro-n-hexylmethacrylate resin in 99.9% FREON-113***

(1,1,2-trichloro-1,2,2 trifluoroethane).

Procedure: 1....