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Laminates, Rigid
Published in Martin W. Jawitz, Michael J. Jawitz, Materials for Rigid and Flexible Printed Wiring Boards, 2018
Martin W. Jawitz, Michael J. Jawitz
FR-2 laminate is produced from multiple plies of cellulose-based paper impregnated with an upgraded high-temperature, flame-retardant, plasticized phenolic resin. In manufacturing the FR-2 laminates, each sheet of cellulose paper is coated twice with the resin. These laminates are generally medium to dark opaque brown in color and should be punched or sheared at slightly elevated temperatures (100°F [38°C]). The FR-2 and XXXPC laminates have similar properties except that the FR-2 is flame-retardant.
Recovery of metals from waste electrical and electronic equipment (WEEE) using unconventional solvents based on ionic liquids
Published in Critical Reviews in Environmental Science and Technology, 2018
Nicolas Schaeffer, Helena Passos, Isabelle Billard, Nicolas Papaiconomou, João A.P. Coutinho
Current research on the use of ILs as WEEE dismantling agent is limited to the disassembly of electrical components and epoxy resin from waste PCBs. PCBs are complex and challenging materials due to their heterogeneous nature. PCBs are comprised of either: (1) an epoxy resin-based plastic reinforced with glass fibers coated with a copper layer (FR-4 type PCB) or (2) a single layer of fiberglass or cellulose paper and phenolic resins coated with a copper layer (FR-2 type PCB). The resin board is overlaid with microelectronic components such as semiconductor chips and capacitors plus solder, which is a Pb-Sn alloy (Zeng, Li, Xie, & Liu, 2013; Zhu et al., 2012c).
PSO AND IFS TECHNIQUES FOR THE DESIGN OF WEARABLE HYBRID FRACTAL ANTENNA
Published in International Journal of Electronics, 2021
Sandeep Singh Sran, Jagtar Singh Sivia
In MKWHFA curve fitting is applied among the feed position (fp) and their related four resonant frequencies (fr1, fr2, fr3 and fr4). With the use of parametric analysis in HFSS software, a set of 94 samples are generated by changing the feed position and their related resonant frequencies. This set of 94 samples is given to the CFR in MATLAB software. CFR generates the following equations (10 to 13) of fr1 to fr4. These equations correspond to the mapping of resonant frequencies with feed position (Rani & Singh, 2012).