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Electron Beam Inspection Method for Ceramic Greensheets

IP.com Disclosure Number: IPCOM000059877D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Chang, TP: AUTHOR [+3]

Abstract

Electrical discontinuities (breaks) in metallic paste lines or vias of ceramic greensheets can be detected by direct inspection with an electron beam. The potential of the electron beam is preferably selected such that breaks which are automatically repaired by the subsequent lamination compression process during fabrication of a multi-layer ceramic chip carrier are not detected. A vector-scan or raster-scan electron beam system may be used in SEM (scanning electron microscope) mode for greensheet inspection. The electron beam deposits charge onto one end of metallic paste vias or lines. If there is electrical continuity to a remote end of a via or line, charge flows to (or from) that point as the potential at the electron beam charging site increases (or decreases) to a value determined by the electron beam potential.

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Electron Beam Inspection Method for Ceramic Greensheets

Electrical discontinuities (breaks) in metallic paste lines or vias of ceramic greensheets can be detected by direct inspection with an electron beam. The potential of the electron beam is preferably selected such that breaks which are automatically repaired by the subsequent lamination compression process during fabrication of a multi-layer ceramic chip carrier are not detected. A vector-scan or raster-scan electron beam system may be used in SEM (scanning electron microscope) mode for greensheet inspection. The electron beam deposits charge onto one end of metallic paste vias or lines. If there is electrical continuity to a remote end of a via or line, charge flows to (or from) that point as the potential at the electron beam charging site increases (or decreases) to a value determined by the electron beam potential. The potential at the remote end (or charge flowing to or from that end) then may be detected to determine whether electrical continuity exists. Detection of the potential at a remote end can be accomplished by probing the remote end with an electron beam and detecting the secondary electron yield with a backscattering electron detector. A direct mechanical contact to the remote end site can be used also. A large area contact to the back side of a greensheet may be used to collect charge flowing to the backside along lines and through vias to form a signal current. A display of back side collec...