Plated through via defects and their influence on fatigue life.
Published: 2006
Language: eng
Number of pages: 120
ISBN-13: 9780494212745
Description: Nano-indentation experiments on cross-sectioned barrels showed that thinner plating results in a slightly increased nano-indentation hardness, a property related to the yield strength.Finite element analysis (FEA) were used to develop correlations that can be used to calculate the stress concentration factors (SCFs) for five typical defects found in plated-through-vias (PTVs) as a function of various geometric parameters. In terms of their severity, the defects were ranked as: (1) rapid thickness reduction (SCF&le;13), (2) occasional waviness (SCF&le;4.6), (3) gradual thickness reduction (SCF&le;4), (4) wicking (SCF&le;4) and (5) waviness (SCF&le;3.1). The SCF due to an internal pad and the influence of an external pad-barrel corner crack were also investigated.Elastic-plastic thermal strain analyses were conducted on perfect and defective vias using FEA and a modified version of an earlier analytical model. Both approaches were in a good agreement for vias with a board to barrel-wall thickness ratio greater than 40.
Notes: Source: Masters Abstracts International, Volume: 45-03, page: 1634.

Thesis (M.A.Sc.)--University of Toronto, 2006.

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