Browse Prior Art Database

Constant Force Electrical Connector

IP.com Disclosure Number: IPCOM000122008D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Gillett, JB: AUTHOR

Abstract

This article solves the problem of maintaining a constant normal force on a connector in an area array over a wide deflection range. BACKGROUND:

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 58% of the total text.

Constant Force Electrical Connector

      This article solves the problem of maintaining a constant
normal force on a connector in an area array over a wide deflection
range.
BACKGROUND:

      When it is required to join two planar surfaces with an area
array interposer connector, the lack of parallelism and planarity of
the two surfaces leads to a large tolerance in the deflection of the
individual connector elements between the surfaces.

      An example of a connector element is seen in Fig. 1, a
spring/pin designed by Augat Corp.  This force increases strongly
with deflection.  A specified minimum force is required to ensure
good contact resistance, but variability in the amount of deflection
(caused by lack of parallelism) often produces an ideal high force at
the extreme of the tolerance.  An ideal force vs. deflection
characteristic would provide a constant force over the full range of
deflection.
DESCRIPTION:

      Augat's design shows a two-piece connector element in which
formed springs in the upper piece ride on a conical ramp in the lower
piece as the element is compressed between two surfaces.  The design
shown in Fig. 2 changes the slope of the ramp from a straight line to
a curve whose slope is steepest adjacent to the starting position of
the spring on the ramp and is shallowest at the remote (finishing)
position.

      Under a compressive force along the x axis, the spring rides up
the ramp and produces a force Fs, the product of...