Hi Seth,
No, not all PWBs out there are time bombs. PWBs with aspect ratios much
larger than 10:1 have and can be successfully made. Actually, the aspect
ratio is only used as an attention flag, hole diameter and PWB thickness
independently are the real important parameters. As these parameters move
towards lower diameters and thicker PWBs, more attention needs to be paid to
assure good quality, to prevent excessive T-excursions [manual soldering],
and specing thick enough plating.

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], Website: www.engelmaier.com

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