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Reply To: | TechNet E-Mail Forum. |
Date: | Fri, 26 Feb 1999 10:55:49 EST |
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Hi Bryan,
Innerlayer (post) separation is indeed more likely to occur for PTvs with
fewer internal lands, particularly for larger diameter PTVs. The lands act as
stiffening ribs resisting the compressive forces on the PTV barrel from the
hydrostatic pressures generated by the expanding resin. Less ribs (lands) will
result in larger hoop forces on the lands that remain. This can be critical
for thin inner layers and those made of E1 foil.
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 904-437-8747, Fax: 904-437-8737
E-mail: [log in to unmask]
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