Browse Prior Art Database

Improved Pin Attachment Structure

IP.com Disclosure Number: IPCOM000104530D
Original Publication Date: 1993-Apr-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 1 page(s) / 37K

Publishing Venue

IBM

Related People

Shih, D: AUTHOR [+2]

Abstract

A pin attachment structure is described to produce a low stress pin joint on a ceramic substrate. The provided structure comprises a plurality of metal layers which are deposited on a ceramic substrate after the completion of the firing process.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Improved Pin Attachment Structure

      A pin attachment structure is described to produce a low stress
pin joint on a ceramic substrate.  The provided structure comprises a
plurality of metal layers which are deposited on a ceramic substrate
after the completion of the firing process.

      To fabricate the low stress pin joint, a thin layer of solder
with controlled thickness and volume may be deposited atop the
previously fabricated Bottom Surface Metallurgy (BSM) pads or on the
pin head or on both.

      Preferably, particular pins known in the art for use with
ceramic substrates which are comprised of a Ni-Fe alloy (such as 36%
Ni, and 64%  Fe) or a Ni-Fe-Co alloy, are used in conjunction with
the ceramic substrate.  One of the layers which may be placed on the
pin or as an additional layer on the multi-layer thin films is a 10
to 75 micron solder alloy layer for joining the pin to the ceramic
substrate.  Preferably, the solder alloy layer is comprised of a
lead-tin alloy with 3-10%  tin, or a gold-tin alloy with 75-95%
gold.  Small amounts of third elements may be added to the chosen
alloy to modify the thermal stress and mechanical strength properties
of the alloy as desired.  The solder layer may be fabricated by
co-evaporation, co-sputtering, using pre-fabricated preforms, or
other known processes.  If desired, a last layer comprised of gold
may be deposited on the solder layer.  The thickness of the gold
layer should be greater than 1000 Ang...