Copper coin-embedded printed circuit board for heat dissipation: manufacture, thermal simulation and reliability

Purpose - The purpose of this paper is to form copper coin-embedded printed circuit board (PCB) for high heat dissipation. Design/methodology/approach - Manufacturing optimization of copper coin-embedded PCB involved in the design and treatment of copper coin, resin flush removal and flatness control. Thermal simulation was used to investigate the effect of copper coin on heat dissipation of PCB products. Lead-free reflow soldering and thrust tests were used to characterize the reliable performance of copper coin-embedded PCB. Findings - The copper coin-embedded PCB had good agreement with resin flush removal and flatness control. Thermal simulation results indicated that copper coin could significantly enhance the heat-dissipation rate by means of a direct contact with the high-power integrated circuit chip. The copper coin-embedded PCB exhibited a reliable structure capable of withstanding high-temperature reflow soldering and high thrust testing. Originality/value - The use of a copper coin-embedded PCB could lead to higher heat dissipation for the stable performance of high-power electronic components. The copper coin-embedded method could have important potential for improving the design for heat dissipation in the PCB industry

Characterization and application of aggregated porous copper oxide flakes for cupric source of copper electrodeposition

Copper oxide was prepared with thermal decomposition of basic copper carbonate to complement the concentration of cupric ions for copper electrodeposition in a plating system with insoluble anode. Copper oxide particles with a structure of aggregated porous flakes had a wide size distribution ranging from 100 nm to 100 μm. Copper oxide exhibited a dissolution rate of about 15 s in 12.5 vol% H2SO4 solution. During copper electrodeposition, copper deposits with fine growth formed in the electrolyte with stable cupric concentration provided by rapid dissolution of copper oxide

HOTf-Catalyzed, Solvent-Free Oxyarylation of Ynol Ethers and Thioethers

A novel HOTf-catalyzed oxyarylation of ynol ethers and thioethers has been realized with aryl sulfoxides as the oxyarylating reagents, providing α-arylated esters or thioesters in good to excellent yields. Notably, all atoms of the starting materials were incorporated in the product (100% atom economy) and the reaction proceeded under very mild conditions. It was found that the reaction can be ran under air and that the best yields are obtained under solvent-free conditions

Synthesis of α-Nitro Ketoximes from Styrenes and <i>tert</i>-Butyl Nitrite

<div><p></p><p>We have discovered that various α-nitro ketoximes can be synthesized in good yields starting from styrenes and <i>tert</i>-butyl nitrite. The success of the reaction was critically dependent on the use of a mixture solvent of dimethylsulfoxide and water. The reaction can tolerate a wide variety of substituents including electron-withdrawing and electron-donating groups.</p></div

Selective Synthesis of Aryl Nitriles and 3‑Imino-1-oxoisoindolines via Nickel-Promoted C(sp²)–H Cyanations

An efficient nickel-promoted selective monocyanation of benzamides with TMSCN via 8-aminoquinoline directed <i>ortho</i> C–H activation has been developed. Varieties of functionalized <i>ortho</i>-cyanated (hetero)­aryl nitriles can be selectively synthesized in moderate to good yields. These cyanation products can be easily transformed into various 3-imino-1-oxoisoindolines in a one-pot procedure. The mild reaction conditions, use of cheap and commercially available reagents, wide functional group tolerance, and operational convenience make this protocol practical to the synthetic community

Synthesis of Aryl Alkynes via Copper Catalyzed Decarboxylative Alkynylation of 2‑Nitrobenzoic Acids

An efficient protocol for the synthesis of internal aryl alkynes was achieved via Cu-catalyzed decarboxylative cross-coupling reactions, and to the best of our knowledge, this is the first example of a Cu-catalyzed decarboxylative alkynylation of benzoic acids with terminal alkynes. This approach utilizes simple Cu salt as catalyst and O₂, an abundant, clean, and green material, as the oxidant. The reaction tolerates various functional groups, and a variety of internal aryl alkynes were synthesized in 46–83% yields