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Browse Prior Art Database

Spring Probe Test Head With Multipoint Blade Contact

IP.com Disclosure Number: IPCOM000102254D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 3 page(s) / 90K

Publishing Venue

IBM

Related People

Brzozowski, W: AUTHOR [+5]

Abstract

The usual testing technique for contact electrical shorts and opens testing on electronic circuitry is to contact each individual circuit element with mechanical probes. This is accomplished by aligning a probe, most often spring-loaded or buckling beam, to a 5- to 16-mil test pad on the extremes of the circuit to be tested. This requires the product design to be such that test pads can be placed on the product.

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This is the abbreviated version, containing approximately 52% of the total text.

Spring Probe Test Head With Multipoint Blade Contact

       The usual testing technique for contact electrical shorts
and opens testing on electronic circuitry is to contact each
individual circuit element with mechanical probes.  This is
accomplished by aligning a probe, most often spring-loaded or
buckling beam, to a 5- to 16-mil test pad on the extremes of the
circuit to be tested.  This requires the product design to be such
that test pads can be placed on the product.

      In various TAB products, test pads are placed on the Outer Lead
Bonds (OLBs) but not the Inner Lead Bonds (ILBs). This is where the
basic probing problem occurs - the ILBs are too close together for
conventional contact probing. Two methods are disclosed that allow
the testing of various TAB configurations.

      Figure 1 is a conceptual drawing of a test head that is used
when the majority of the ILB area is not available for electrical
contact.  The head has been designed with many of the same features
as found in traditional concepts or prior art.  Ten-mil diameter
spring-loaded probes are used for contacting test pads in the OLB
region as well as the chip site power and ground busses.  Only probe
locations are shown in Figure 1 for clarity.  The unique aspect of
the head and the element that differs from prior art is the method
for contacting the ILBs.  A blade contact has been designed that
allows the simultaneous probing of groups of ILBs (see Figure 2) at
the ILB extremes.  This is accomplished without the necessity of test
pads.

      There are three major components of the blade contact concept:
t...