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Conformal Polish of Glass Ceramics

IP.com Disclosure Number: IPCOM000109782D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Carr, JW: AUTHOR [+2]

Abstract

This article describes a technique which permits polishing of glass ceramic substrates without planarization.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 58% of the total text.

Conformal Polish of Glass Ceramics

       This article describes a technique which permits
polishing of glass ceramic substrates without planarization.

      Conventional treatment of glass ceramic substrates required
planarization before polishing could take place.  During the
planarization step the amount of material removed depended upon the
total camber of the part.  As a result of green sheet thickness and
the problem of punch breakout, a practical limit for material removal
is approximately 2.3 mils.  Typically, a majority of substrates
exhibit global camber exceeding 2.5 mils and are discarded.

      The technique discussed herein permits the polishing of glass
ceramic substrates without planarization.  Surface roughness after
polishing is less than 5/ nanometers / 25 micrometers while global
camber is preserved.  The key to conformal polishing is the use of a
pliable backing material under a soft pad.  The thickness of the
composite pad allows access to deeply recessed regions of the
substrate surface.  In addition, the process parameters are
controlled to give the pad time to respond to the surface topography.

      Referring to Fig. 1 which is a top view of the polishing table
and pads, when travelling in the same direction, at point A, the
speeds of the table and quill are matched.  The velocity differential
between the pad and the substrate is small, giving the pad time to
respond to irregularities in the substrate surface.  When the...