Browse Prior Art Database

Module Protection, C4 Life Extension And Chip Reworkability Using Parylene

IP.com Disclosure Number: IPCOM000121026D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 34K

Publishing Venue

IBM

Related People

Babich, ED: AUTHOR [+8]

Abstract

Disclosed is a method for protecting microelectronic structures from environmental corrosion and for enhancing the lifetimes of solder joints via the chemical vapor deposition of Parylene (Union Carbide). In addition, a process for reworking the Parylene-coated structures containing the solder joints is disclosed.

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Module Protection, C4 Life Extension And Chip Reworkability Using
Parylene

      Disclosed is a method for protecting microelectronic
structures from environmental corrosion and for enhancing the
lifetimes of solder joints via the chemical vapor deposition of
Parylene (Union Carbide).  In addition, a process for reworking the
Parylene-coated structures containing the solder joints is disclosed.

      As an example, the Parylene was deposited on ceramic carriers
with chips joined via IBM controlled collapse solder technology.  It
was found through room temperature resistance measurements that
Parylene encapsulation enhances the lifetimes of the solder joints
during liquid nitrogen cycling.  These Parylene coated carriers were
also found to be reworkable using a process consisting of chip
pulling, oxygen RIE (or possibly, ashing) of the Parylene, solder
dressing, chip joining and Parylene re-deposition.  For chip carriers
supporting thin polymer structures (e.g., thin film chip carriers and
printed circuit boards), the above rework procedure still applies so
long as the carrier contains an etch stop layer protecting the
polymer structure during oxygen RIE.