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Optical Pressure Block for Fine Pitch Probe Tester

IP.com Disclosure Number: IPCOM000110369D
Original Publication Date: 1992-Nov-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Goodman, D: AUTHOR [+2]

Abstract

Electrical probing can be performed while viewing the circuit being tested by using a portion of a clear hemisphere with the probe structure on the bottom.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 98% of the total text.

Optical Pressure Block for Fine Pitch Probe Tester

       Electrical probing can be performed while viewing the
circuit being tested by using a portion of a clear hemisphere with
the probe structure on the bottom.

      The center of the spherical surface is at the object plane, so
that the imaging is free of spherical aberration, coma, and axial
color, no matter what the radius of curvature of the sphere.  If the
field of view is small enough, the image quality is not appreciably
affected by this component.  (A thick plane parallel plate, on the
other hand, would introduce considerable chromatic and spherical
aberration.)  Consequently, this unit can be used with existing
long-working distance microscopes, no change in aberration balance
being required.

      Illumination can be provided in several ways.  The figure shows
a darkfield arrangement, where the light enters through the same
surface as that through which the part is viewed.  Another method of
illumination, as indicated by the dashed lines, is through an
auxiliary surface.

      The bottom of the unit can be configured in various ways,
depending on the particular application.  It may be introduced
through the microscope, through the spherical surface, or through an
auxiliary port.

      The bottom of the unit can be configured in a variety of ways,
depending on the probe arrangement.  For example, the block may be
flat or stepped.  The electrical probes may be attached to the bloc...