Browse Prior Art Database

Low-Cost Silver-Palladium Braze for Pin Grid Array Modules

IP.com Disclosure Number: IPCOM000115960D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

Baska, DA: AUTHOR [+2]

Abstract

An economical, high reliability Silver-Palladium (Ag-Pd) brazing alloy and preferred pin attach materials configuration for metallurgical bonding of pins to Pin Grid Array (PGA) Single Chip Modules (SCMs) and Multichip Modules (MCMs) is described. This braze and pin materials configuration can be used to replace expensive Gold-Tin (Au-Sn) brazing methods.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Low-Cost Silver-Palladium Braze for Pin Grid Array Modules

      An economical, high reliability Silver-Palladium (Ag-Pd)
brazing alloy and preferred pin attach materials configuration for
metallurgical bonding of pins to Pin Grid Array (PGA) Single Chip
Modules (SCMs) and Multichip Modules (MCMs) is described.  This braze
and pin materials configuration can be used to replace expensive
Gold-Tin (Au-Sn) brazing methods.

      Many Ceramic Pin Grid Array (CPGA) packages require use of
expensive Gold-Tin (Au-Sn) braze materials for metallurgical bonding
of Nickel-Gold (Au-Ni) overplated  pins to interconnection pads on
ceramic SCM and MCM packages (Fig. 1).  However, substantial cost
savings can be realized without sacrificing reliability if an
alternative, Au-free, braze material is used to bond Ni overplated
pins directly to SCM or MCM package bodies.  In order to provide a
reliable, Au-Free braze configuration, a suitable Au-Free pin braze
alloy must possess the following primary attributes:
  o  The braze material must possess high corrosion/migration
      resistance.
  o  The braze material melting point must be compatible with high
      temperature, post braze processes used on modules.
  o  The braze material must possess good wetting characteristics to
Ni.
  o  The braze material must possess adequate strength and fatigue
      resistance.

      The development of a Silver-Palladium (Ag-Pd) braze alloy along
with use of a pin...