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 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

Nitrogen (N2) removal in gas separation using polysulfone membrane

The development of membrane separation process in gas separation process has recently gained numerous interests from industries. With low capital and operating cost, operational simplicity, high reliability, space efficiency and environmental friendly, the membrane technology is the best candidate to replace traditional gas separation methods. Polysulfone polymer potentially, can be use as membranes for nitrogen removal in gas separation with very high mechanical and thermal strength which can be applied at wide range of temperature and pressure. The polysulfone membrane was prepared by mixing polysulfone pellet with N,N-dimethylacetamide (DMAc) solvent to dilute the polymer before it is cast using casting knife into smaller samples. Samples of membrane with different polymer composition were produce. Then the already cast membrane was immersed in different coagulation bath and finally the samples undergo permeability test using membrane permeation unit to etermine the permeability and selectivity of each membrane. High polymer composition and coagulation bath temperature will produce high selectivity membrane but low permeability membrane and so vice versa. The most ideal membrane must have high permeability and selectivity. Thus, the olysulfone membrane with 25wt% polymer composition immersed in room temperature tap water, is chosen as the best membrane to separate N 2 from CO 2,02,and C114