The effect of nickel doping on SAC305 lead-free solders and EN(B)EPIG surface finish
Recently, there are many portable electronics product such as i-pad, smart phone and tablet were widely used due to growing needs of busy lives and demandin& more functionalities and compatibility. The growing of these smart technologies made electronic packaging are moving parallel with current...
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| Main Authors: | , , |
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| Format: | Conference or Workshop Item |
| Published: |
2014
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/6501/ http://eprints.uthm.edu.my/6501/1/The_effect_of_nickel_doping_on_SAC305.pdf |
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| Summary: | Recently, there are many portable electronics product
such as i-pad, smart phone and tablet were widely used due
to growing needs of busy lives and demandin& more
functionalities and compatibility. The growing of these smart
technologies made electronic packaging are moving parallel
with current technology and expanding rapidly because of
global competitive pressure. Thus, flip chip technology is
one of the important element need to be considered in order
to produce high performance and quality of electronic
devices due to shorter electrical connections between the
chip and substrate and very high input/output capacity and
the smallest possible package size. In flip chip applications,
solder bump was used to connect the die to the substrate or
circuit board. The addition of doping element in lead-free
solder has been discussed have a big influence on the solder
joint quality including solder microstructure. It also can
enhanced the properties and improve the performance of
interfacial reaction at interface and made a reliability of
lead-free solder especially on Sn-3.0Ag-0.5Cu was
increased. Therefore, this study investigates the effect of
nickel doping on Sn-3.0Ag-0.5Cu (SAC305) lead-free
solders and electroless nickel (boron)/electroless
palladium/immersion gold (EN(B)EPIG) surface finish. In
this study, two types of lead-free solders was used which are
Sn-3.0Ag-0.5Cu (SAC305) and Sn-3.0Ag-0.5Cu-0.05Ni
(SACN30505) with solder size diameter of 500 pm in order
to examine the effect ofnickel on interfacial reaction during
soldering process. Reliability of solder joint has been
assessed by performing solid state isothermal aging at 125"C
for 250, 500, 1000 and 2000 hours. Several charccterization
techniques will be conducted including image analyzer,
optical microscope, field emission scanning electron
microscopy and enerry dispersive x-ray analysis to
characterize the intermetallic formed. After reflow soldering
process, it was found that the (Cu,Ni)6Sn5 and (Ni,Cu)3Sna
intermetallic compound (IMC) is formed at interface.
(Ni,Cu):Snq dominates in the outside of solder joint while
(Cu,Ni)6Sn5 dominates in the centre of joints.Besides that,
after soldering and isothermal aging process, SAC305 solder
with additions of 0.05%o of Ni (SACN30505) made the
intermetallics grew slightly faster than in the solder without
Ni additions. Hence, analysis by optical microscope revealed
that the IMC thickness of the SACN30505 solder produced
thicker IMC compared to SAC305 for both situations. This
observation is confirmed by the increase in grain size of
intermetallics with Ni additions. Moreover, aging time
resulted in an increase in thickness and changed the
morphology into more spherical, dense and large grain size.
In addition. the results also revealed that the thickness of
intermetallics formed is proportional to the aging duration. |
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