Development Of Ternary Ni-Ag-P And Ni-Cu-P Using Electroless Coating On Copper Substrate
Current functional test of assembled device in semiconductor industry use thermal interface media but it occasionally caused cosmetic defects such as stain or scratch mark. A possible solution to eliminate the undesired defects is by improving the nickel-phosphorus (Ni-P) coating currently applied o...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2015
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| Subjects: | |
| Online Access: | http://eprints.usm.my/46917/1/Development%20Of%20Ternary%20Ni-Ag-P%20And%20Ni-Cu-P%20Using%20Electroless%20Coating%20On%20Copper%20Substrate.pdf http://eprints.usm.my/46917/ |
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| Summary: | Current functional test of assembled device in semiconductor industry use thermal interface media but it occasionally caused cosmetic defects such as stain or scratch mark. A possible solution to eliminate the undesired defects is by improving the nickel-phosphorus (Ni-P) coating currently applied on the test chuck in terms of the ability to conduct heat transfer efficiently and thus eliminate the use of thermal interface media. Co-deposition of argentum (Ag) and copper (Cu) into Ni-P coating are expected to improve the thermal conductivity of Ni-P coating without sacrificing other coating’s properties; surface roughness, thickness, hardness and wear resistance. Ni-P coating in this work was prepared via electroless coating on a copper substrate. The experimental work began by developing the coating solution in order to achieve targeted phosphorus content, thickness and surface roughness. To produce ternary nickel-argentum-phosphorus (Ni-Ag-P) and nickel-copper-phosphorus (Ni-Cu-P) coating, argentum and copper salt were added into the coating solution. The best ternary coating was observed on coating containing 5 mg/L argentum sulphate and 10 mg/L copper sulphate with co-deposition of 1.14 wt.% Ag and 3.56 wt.% Cu respectively. Both ternary coating produced have smoother surface with lower wear rate compared to binary Ni-P coating. Improvement in wear resistance is related to the hardness of coating, in which Ni-Ag-P has highest hardness (394.08 HK) followed by Ni-P (380.78 HK) and Ni-Cu-P (365.34 HK). Even though Ni-Cu-P coating possess low hardness, its low surface roughness contributed to the low wear rate. The thermal conductivity for ternary Ni-Ag-P coating (451.10 W/m.K) was higher than Ni-P (445.70 W/m.K) and Ni-Cu-P coating (326.91 W/m.K). The result is as expected as argentum has higher conductivity compared to nickel, and thus addition of argentum is able to improve thermal conductivity of Ni-P coating. |
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