In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 19, No. 8 ( 2004-08), p. 2428-2436
Abstract:
Intermetallic compound (IMC) spalling from electroless Ni-P film was investigated with lead-free solders in terms of solder-deposition methods (electroplating, solder paste, and thin foil), P content in the Ni-P film (4.6, 9, and 13 wt% P), and solder thickness (120 versus .200 μm). The reaction of Ni-P with Sn3.5Ag paste easily led to IMC spalling after 2-min reflow at 250 °C while IMCs adhered to the Ni-P layer after 10-min reflow with electroplated Sn or Sn3.5Ag. It has been shown that not only the solder composition but also the deposition method is important for IMC spalling from the Ni-P layer. The spalling increased with P content as well as with solder volume. Ni 3 Sn 4 intermetallics formed as a needle-shaped morphology at an early stage and changed into a chunk-shape. Needle-shaped compounds exhibited a higher propensity for spalling than chunk-shaped compounds because many channels among the needle-shaped IMCs facilitated Sn penetration. A reaction between the penetrated Sn and the Ni 3 P layer formed a Ni 3 SnP layer and Ni 3 Sn 4 IMCs spalled off the Ni 3 SnP surface. Dewetting of solder from the Ni 3 SnP layer, however, did not occur even after spalling of most IMCs.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/JMR.2004.0297
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2004
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8
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