Browse Prior Art Database

Anti-Crosstalk Via Hole Verifier

IP.com Disclosure Number: IPCOM000099285D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 87K

Publishing Venue

IBM

Related People

Shumate, JR: AUTHOR [+3]

Abstract

This article describes a via hole verifier that uses a matrix of individual light-emitting (LEDs) instead of one overall light source and assembly. In mechanism disclosed herein, the LEDs are arranged in a matrix that exactly duplicates the set that is used with any particular greensheet part There will be as many different LED assemblies as are different punch assemblies.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Anti-Crosstalk Via Hole Verifier

       This article describes a via hole verifier that uses a
matrix of individual light-emitting (LEDs) instead of one overall
light source and assembly.  In mechanism disclosed herein, the LEDs
are arranged in a matrix that exactly duplicates the set that is used
with any particular greensheet part  There will be as many different
LED assemblies as are different punch assemblies.

      There will also be a matrix of photo-sensors that is in the
exact same pattern as the punches.  The LED are mounted above the
greensheet in the cavity that the existing light source and reflector
and the photo-sensor matrix is mounted beneath the  This mechanism
can be extended to work with a of high-precision sensors in order to
detect clogged holes in the greensheets.

      Two greensheets at a time are handled by auto-punch and they
are both under the control of one X-Y stage.  One sheet is being
verified at the same as the next sheet is being punched.  The sheet
being is thus being moved from position to position in the same
pattern as the sheet being punched.  The of this disclosure turns on
LEDs in the same exact as the punches that are being energized.  When
any are being held back during a punch cycle, the LEDs will not be
energized.  The photo-sensors will be sensed in the same pattern as
the punches and LEDs.  This means that any particular photo-sensor
will be sampled unless its corresponding LED has been  The physical
spacing between punches is to prevent any optical crosstalk between
the LEDs and their corresponding sensors.  This allows machine to run
at its maximum speed, because t...