Effect of nano-TiO2 addition on the microstructure and bonding strengths of Sn3.5Ag0.5Cu composite solder BGA packages with immersion Sn surface finish

Morphology and Shear Strength of Lead-Free Solder Joints with Sn3.0Ag0.5Cu Solder Paste Reinforced with Ceramic Nanoparticles

“…5). Similar behavior was reported in many previous studies 8,11,12,23 and explained based on the theory of adsorption of a surface-active material. This means that the addition of ceramic nanoparticles increases the content of surface-active material in the solder joint and maximizes the amount of adsorbed particles on the IMC surface.…”

“…A similar trend was reported in Ref. 12 for SAC solder joints with up to 1.25 wt.% of TiO 2 nanoadditions using Cu pads plated with 0.2 lm Sn. An insignificant decrease of the average thickness of the IMC layer at the interface solder/OSP-Cu was reported by adding 1 wt.% nano ZrO 2 into SAC305 solder powder.…”

“…For instance, the shear strength of SAC solder joints was reduced for contents of more than 1.0 wt.% of nano SiO 2 11 and nano TiO 2 . 12 It was supposed that an agglomeration occurs to decrease the high surface energy of nanoparticles. As a result, this sideeffect is responsible for a reduction of the improving effects, because nanoparticle agglomerates are generated both in the solder matrix and at the interface solder/substrate in the solder joints.…”

Corrosion resistance of Pb-free and novel nano-composite solders in electronic packaging

“…The thickness of the Cu 6 Sn 5 IMC layer was reduced by 51%. The results indicate that the growth of the Cu 6 Sn 5 IMC layer at the solder/pad interfaces of Sn3.5Ag0.5Cu is depressed through the small addition of nano-TiO 2 particles [58]. With the addition of 0.5-1 wt% nano-TiO 2 particles, fracture occurred in all of the solder joints as cracks propagated through the Sn3.5Ag0.5Cu composite solder balls, which ruptured mostly along the submicro Ag 3 Sn IMC and solder matrix, as shown in Fig.…”

“…However, large Ag 3 Sn IMCs were not observed in the Pb-free SAC solder. Another, author reported that the effects of nano-TiO 2 particles on the interfacial microstructures and bonding strength of Sn3.5Ag0.5Cu nano-composite solder joints in ball grid array (BGA) packages with immersion Sn surface finishes [58]. It is clearly shown in Fig.…”