Technical Library | 2022-01-05 23:14:20.0
The process of copper recovery from waste printed circuit board has generated large amounts of non-metallic fraction (NMF) residue. In this research, the residue was recycled as a substitute for fine aggregates at 0%, 5%, 10%, 15%, and 20% to produce interlocking concrete blocks. Properties of the interlocking concrete blocks produced in this study, such as density, water absorption, compressive strength, were firstly examined and the selected mixes were further evaluated for the heavy metal leachability.
Technical Library | 2016-01-12 11:03:35.0
With the pitch size of interconnect getting finer and finer, the bonding strength between flexible and rigid (e.g. PCB, ceramic) substrates becomes a serious issue because it is not strong enough to meet the customer’s requirement. Capillary underfill has been used to enhance the bonding strength between flexible and rigid substrates, but the enhancement is very limited, particularly for high temperature application. The bonding strength of underfilled flexible/rigid interconnect is dramatically decreased after being used at 180◦C, and the interconnects are weakened by the internal stress caused by the expansion of underfill at high temperatures. In order to resolve reliability issues of the interconnect between flexible/rigid substrates, solder joint encapsulant was implemented into the thermal compression bonding process, which was used to manufacture the interconnect between flexible/rigid substrates. Compared to the traditional process, the strength of the interconnect was doubled and the reliability was significantly improved in high temperature application.
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