A. Eslambolchi, P. Johnson, M. Kaufmann och Z.
Mei, Electroless Ni/Immersion Au
Evaluation – Final Program Report, Electronic Assembly Development Center,
Hewlett-Packard, Palo Alto, 1998.
K. Zeng och K.N. Tu, Six Cases of Reliability Study of Pb-free
Solder Joints in Electronic Packaging Technology, Materials Science and
Engineering R, Vol. 38, 2002, sida 55-105.
A. Zribi, R.R. Chromik, R. Presthus, K. Teed,
L. Zavalij, J. DeVita, J. Tova, E.J. Cotts, J.A. Clum, R. Erich, A. Primavera,
G. Westby, R.J. Coyle och G.M. Wenger, Solder Metallization Interdiffusion in
Microelectronic Interconnects, IEEE Trans. on Comp. and Pack. Techn. Vol.
23, Nr. 2, 2000, sida 383-387.
R. Darveaux, K. Banerji, A. Mawer och G. Dody,
Reliability of Plastic Ball Grid Array
Assembly, J.H. Lau (Ed.), Ball Grid Array Technology, McGraw-Hill, Inc.,
1995, Kapitel 13.
A.M Minor och J.W. Morris, Jr., Growth of Au-Ni-Sn Intermetallic Compound on
the Solder-Substrate Interface After Aging, Metall. Mater. Trans, A, 31A,
2000, p. 789. http://www.lbl.gov/morris/private/papers.html
A.M. Minor och J.W. Morris, Inhibiting Growth of the
Au0.5Ni0.5Sn4 Intermetallic Layer in Pb-Sn
Solder Joints Reflowed on Au/Ni Metallization, Journal of Electronic
Materials, October 2000, Vol. 29, Issue 10, sida 1170-1174. http://www.lbl.gov/morris/private/papers.html
Per-Erik Tegehall
IVF, Sweden
The firgure reported by Glazer
from Hp for gold embrittlement was 3% and not 0.3%. The total amount of gold
in ENIG if the new IPC 4552 specification is followed is less than 5
micro-inches or 0.12 microns.
If one does the math, then it is evident that
under these conditions "Solder Joint Gold Embrittlement" is a non issue
for ENIG.
Of course this is all on the board side and not the component. If
there is an issue with component side separation, the target investigation
should not be on ENIG leaving the true cause unidentified or
addressed.
Blaming the ENIG finish idiscrimanetly, and using the "black
Pad" as a catch all leaves a lot of areas, where things could go wrong,
unidentified and more important not corrected.
Blaming the "Black pad" is
prevalent. I often wonder how prevalent the ture cases of "Black Pad"
are?
George Milad
Uyemura International Corp
Chairman IPC Plating
Commitee
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