4-Pole Contacting Unit
Original Publication Date: 1995-Mar-01
Included in the Prior Art Database: 2005-Mar-30
Kocher, G: AUTHOR [+3]
This article describes a test probe which can be used for "Flying Probe Test" in packaging products (cards, boards, MCMs).
4-Pole Contacting Unit
describes a test probe which can be used for
"Flying Probe Test" in packaging products (cards, boards, MCMs).
probe described herein only one contact point is
contacted at a time. It can be moved freely over the complete
surface of the product to be tested and can thus be directed to any
position. If two or more of these probes are used at the same time,
all contact points, even those which are arranged very closely, can
probe is made of several contact beams being made of
resilient beams (CuBe, special alloy, etc.). These beams are
arranged in pairs and are guided in a suitable housing. Furthermore,
the beams are individually surrounded by an insulating layer.
Fig. 1 shows a front view of the respective
The first pair of contact beams is arranged so that it impinges on
the front side of the pad to be tested. It is guided in the housing
such that it functions as a buckling beam. Suitable chambers are
arranged in the housing allowing the controlled buckling of the
beams. The contact pressure as well as the desired contact path can
be predetermined by respective choice of the number and the size of
Since the two
beams are guided individually, an optimal
adjustment of different topographies of the pruduct to be tested can
be achieved without having to accept differences relating to the
contact characteristics (contact pressure) of the two beams.
The two beams
that contact a pad are always isolated.
allows a verification of the contact between the test probe and the
part to be tested. By means of "double contacting" of a pad a four
point measurement of a grid can be achieved.
contacting the pad the beams protrude slightly from their
guide. This results in a so-called "stripping effect" which is
helpful for the removal of particles (self cleaning).
The beams are
clamped mechanically in the housing directly
above the buckling length (Fig. 1). This clamping is detachable,
allowing an elongation of the beams in the direction of contact in
case they should be worn-out.
The second pair of beams, in relation to the f...