Browse Prior Art Database

Non-Contact Method for Measuring Plating Thickness

IP.com Disclosure Number: IPCOM000112728D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 91K

Publishing Venue

IBM

Related People

Christmas, HF: AUTHOR [+4]

Abstract

Described is a fixture using non-contacting pneumatic gage heads to measure variations in the thickness of a thin, fragile copper mask used in the production of multilayer ceramic chips. Such variations, occurring across the surface of the mask, are generally due to variations in the thickness of nickel plating applied to the mask.

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Non-Contact Method for Measuring Plating Thickness

      Described is a fixture using non-contacting pneumatic gage
heads to measure variations in the thickness of a thin, fragile
copper mask used in the production of multilayer ceramic chips.  Such
variations, occurring across the surface of the mask, are generally
due to variations in the thickness of nickel plating applied to the
mask.

      Fig. 1 is a top view of this fixture, while Fig. 2 is a side
view.  As shown in these Figures, the fixture 10 includes a lower
portion 12 to which a top portion 14 is pivotally mounted at hinges
16.  Top portion 14 includes five pneumatic gage heads 18 for
performing the measurements.  Satisfactory results in this
application have been obtained using the Shaevitz Non-contacting LVDT
Gage Head, #PPD-050, Standard Model.

      The measurement process is begun with fixture 10 open, i.e.,
with top portion 14 pivoted upward at hinges 16.  A copper mask (not
shown) to be measured is placed atop a vacuum table 20 of lower
portion 12, being located within the fixture by several dowels 22.  A
vacuum is then applied to five inserts 24 by means of vacuum lines
26.  Each insert 24 extends through vacuum table 20, being located
directly under a gage head 18, when top portion 14 is closed, so that
the copper mask is held tightly against the vacuum table for an
accurate measurement.  Fixture 10 is then closed, rotating top
portion 14 downward to rest against a gage ball 28, which is used to
ensure repeatable positioning.  A pivotally mounted latch 30, held in
engagement with a pin 32 extending from...