Explore chapters and articles related to this topic
Introduction to Electronic Cooling
Published in Mathew V. K., Tapano Kumar Hotta, Hybrid Genetic Optimization for IC Chips Thermal Control, 2022
Mathew V. K., Tapano Kumar Hotta
A typically PCB, generally known as the substrate board (shown in Figure 1.2), is an electronic board that connects different circuit components. The boards are inexpensive, highly reliable, and compact. The PCBs are made of alternating layers of conducting and insulating materials. In usual practice, these are made of a low thermal conductivity material FR4 (reinforced epoxy laminate sheets, k = 1.35 W/mK). The conducting layers of the board are made of copper foil. The board is coated with a solder mask that is usually green in colour; however, blue and red are the other available colours used for coating the PCB. The unwanted copper foil is then removed from the PCB after etching and then left with the desired copper tracers (wiring of the PCB). The different electronic components are soldered to the pads on the PCB, which are then connected to the tracers. The component size, their mounting on the PCB, and the heat dissipation rate from the PCB are some of the key parameters to be highlighted for the PCB design. For the present analysis, the PCB material is mimicked by a low thermal conductivity material, Bakelite (k = 0.24 W/mK).
Second-Level Packaging Materials
Published in Mitel G. Pecht, Rakesh Agarwal, Patrick McCluskey, Terrance Dishongh, Sirus Javadpour, Rahul Mahajan, Electronic Packaging: Materials and Their Properties, 2017
Mitel G. Pecht, Rakesh Agarwal, Patrick McCluskey, Terrance Dishongh, Sirus Javadpour, Rahul Mahajan
Electrodeposited copper: Electrodeposited (ED) copper foil is the standard copper used in rigid laminates. Sheets of ED copper are electrolytically deposited from the copper anode onto a rotating steel drum cathode from which it is subsequently stripped. The side against the drum is smooth and shiny, while the other side has a grainy matte finish. The copper grains thus formed are elongated perpendicular to the surface of the foil (radial to the drum) providing “teeth” on the copper foil for adhesion with the prepreg resin. The adhesion is improved by oxide treatment or nickel flash. While the elongated grains are good for adhesion, they are not good for tensile strength and resistance to fatigue. To improve ductility and etchability the electrodeposited copper is stress relieved or annealed. Electrodeposited copper foil can have pin holes which can lead to resin bleeding during lamination. Some properties of copper are given in Tables 48-50.
Interconnection Technology
Published in Yufeng Jin, Zhiping Wang, Jing Chen, Introduction to Microsystem Packaging Technology, 2017
Yufeng Jin, Zhiping Wang, Jing Chen
The tape is usually manufactured by a photolithography process etching the copper foil. The thickness of the foil is determined by the precision of the circuit and the strength of the wire as required. The equipment for manufacturing tapes is quite complicated and expensive. Standard commercial tapes from professional companies for integrated circuit packages can be ordered. These tapes can be manufactured into a long tape, which, like a filmstrip, can be rolled for the convenience of automated production.
Multi-scan cyclic voltammetry to roughen the surface of copper foil for application in copper-clad laminates
Published in Transactions of the IMF, 2023
Xinyu Gong, Yujia Chen, Guang Yu, Ni Wang, Wencheng Hu
The surface profile of the matte side in this work is compared to the TEH-18 and SDS-18 commercial copper foils and the tested results are displayed in Figure 8. The roughness measurements include Ra (arithmetic average roughness), Rt (maximum peak to valley height), Rz (mean roughness depth) and Rq (root mean square average), and all samples have a nominal thickness of 18 μm. It is worth noting that the roughness values of the matte side obtained by multi-scan cyclic voltammetry are substantially lower than those of both commercial copper foils. As a result, the authors believe that the produced copper foil has benefits in high-frequency printed circuit board applications.
Electrochemical double-pulse technique to modulate the roughened surface of copper foil for copper-clad laminates
Published in Transactions of the IMF, 2022
Ni Wang, Qi Chen, Xinyu Gong, Wencheng Hu
A CCL comprises copper foil and a resin dielectric layer. This resin dielectric layer is an impregnated material comprising fibreglass cloth, glass fibre, inorganic powder, fire retardant, and synthetic resin. The copper foil, with excellent characteristics in conductivity, weldability and ductility, plays a key role in CCLs.3 The copper foil and resin dielectric layers have to undergo a laminating process to achieve tight bonding. Notably, the adhesive strength between the copper foil and composite substrate is an important parameter for CCL evaluation.