High quality and reliability of integrated circuit packaging is required for automotive applications due to the safety concerns. Therefore, elimination and controlling the package defects which can lead to reliability failure is essential. One of the defects that leads to reliability issue is delamination. This study presents the influence of textured leadframe surfaces on the surface wettability and delamination occurrence in automotive package unit. Standard bare Cu leadframe was used as comparison. The leadframe surface was textured with Ni/Pd/Au-Ag using electroplating technique. The surface morphologies of both bare and textured leadframe were characterized using field-emission scanning electron microscope and optical profiler. The energy dispersive spectroscopy was used to quantify the elemental composition of the samples. All samples went through the wettability test under two conditions, which were room temperature and 175°C. The reliability test of complete package was subjected to moisture sensitivity preconditioning level 1 according to IPC/JEDEC STD 020 and the baking process was performed at 125°C for 24hrs followed by soaking process under the condition of 85°C and 85 of relative humidity. Scanning acoustic tomography according to IPC/JEDEC STD 035 was performed after three cycles of infrared reflow at 260°C. Higher surface roughness was observed for pre-plated leadframe (PPF) compared with bare leadframe. The lowest value of average contact angle (∼55°) was observed for PPF at 175°C indicated better wettability feature. Furthermore, no delamination occurrence was observed for PPF sample compared with bare copper leadframe. The obtained result reveals that leadframe with textured surface of Ni/Pd/Au-Ag improved interfacial surface adhesion which eliminated the delamination defect and thus improved the package robustness and reliability.
Raw water treatment and coal-based power generation facilities produce a high level of waste to the environment annually. A low recycling scheme has worsened the situation and wastes usually end up in a landfill. Further environmental degradation could be prevented by re-utilising wastes for the production of alternative bricks. Additionally, the development of low-fired brick from wastes can comparatively reduce energy consumption during the firing stage. Geopolymer has successfully replaced ordinary portland cement (OPC) without bargaining its mechanical quality. This study aimed to investigate the effect of fly ash (FA) content and geopolymerization on mechanical characteristics of brick developed from drinking water sludge (DWS). A set of brick samples was fired at 500 °C while another set of samples was prepared under a high alkaline condition to produce geopolymer bricks. Resultantly, both sets of samples demonstrated a decrease in linear shrinkage and increased density with more content of FA. For fired brick samples, the water absorption decreased from 38.6% to 33.3% before rising again at 45% of FA content. However, a continuous decrease was displayed by geopolymer brick as FA increased. The compressive strength of fired bricks showed a decreasing trend as FA content increased and vice versa for the geopolymer brick. The compressive strength of geopolymer bricks increased from 1.22 MPa to 3.63 MPa at 45% of FA content. Comparatively, geopolymer bricks demonstrated higher strength than fired bricks. These results reflect the advantage of the incorporated wastes and geopolymerisation in developing alternative brick for sustainable resources and a better environment.
Demand for water and energy supply has dramatically increased the amount of drinking water sludge (DW) and fly ash (FA) annually. These wastes should be properly managed and disposed to protect any potential contamination to surrounding ecosystem. Both by-products can be potentially recycled as raw material for brick development. This study aimed to examine the influence of fly ash content on mechanical properties of drinking water sludge brick at low firing temperature of 500°C. Different ratios of FA content were added to the DWS ranged between 0 and 45%. Brick sample was moulded in 215 mm x 102.5 mm x 65 mm dimension. Samples were air-dried prior to firing at 500°C for 3 hours in a furnace. Basic characterization of DW and FA showed pH of 5.76 and 10.1 with organic contents of 8.42% and 1.14%, respectively. Clay and silt fractions were dominant in DWS while silt more apparent than sand and clay in FA. The volume changes and water absorption of the brick samples decreased with increasing FA content. For the water absorption of the brick increased back as 40% of FA content. The density and compressive strength dropped with the increasing amount of FA. The compressive strength of brick experienced with sulphate attack also decreased with increasing FA content. The results suggested that further study are needed to improve the compressive strength of the studied bricks.
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