Browse Prior Art Database

Buckling Beam Planarization

IP.com Disclosure Number: IPCOM000121439D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 38K

Publishing Venue

IBM

Related People

Beaumont, GD: AUTHOR [+2]

Abstract

Electrical testing is performed on substrates before they are used for mounting chips and other circuit elements by bringing a probe consisting of an arrangement of pins into contact with the substrate. The pins may be physically bent as pressure is applied to them to ensure that good electrical contact is made with the substrate. Thus, the pins are referred to as buckling beams.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 85% of the total text.

Buckling Beam Planarization

      Electrical testing is performed on substrates before they
are used for mounting chips and other circuit elements by bringing a
probe consisting of an arrangement of pins into contact with the
substrate. The pins may be physically bent as pressure is applied to
them to ensure that good electrical contact is made with the
substrate. Thus, the pins are referred to as buckling beams.

      In performing the tests it is desirable to have the beams the
same length and the ends of the beams in contact with the substrate
should be flat so as to contact as much surface area of the substrate
as possible.  This increases the likelihood of electrical contact
with the substrate during testing by overcoming any effects from
surface variations of the substrate. This is referred to as
planarization of the buckling beams.

      Previously, planarization of the beams was achieved by bringing
the ends of the beams into contact with sandpaper which was attached
to a sliding plate with tape. The sliding motion of the sandpaper
slowly removed material from the end of the beams to thus make them
of equal length. However, the edges of the ends of the beams became
rounded eventually leaving only approximately 66% of the end surface
of the beam to make contact with the substrate. The edges became
rounded because the beams wore grooves in the sandpaper with the loss
of some of the grit and this was accelerated by the cushion effect of
the tape and sand...