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In this work, electrodeposited Ni-W alloys were studied as barrier films between Cu substrate and lead free Sn3.8Ag0.7Cu (SAC387) solder. Wetting angle and spreading rate of SAC387 on Ni-W alloys with different tungsten contents were investigated and compared with that on Ni film deposited from Watt's bath. Ni-W alloy films of about 1.5 to 2.5 mum were deposited from ammonia-citrate bath on copper substrate. Results show solder/Ni-W alloy system and solder/Ni system exhibited almost the same spreading rate and wetting angle. The wetting angle does not change significantly with tungsten content in the range of 11.3 to 18.0 at.%. Metallographic observation reveals that while intermetallic compound on Ni is continuous, that on Ni-W alloy film is discontinuous.