Copolymer of Pyrrole and 1,4-Butanediol Diglycidyl as an Efficient Additive Leveler for Through-Hole Copper Electroplating

Liu

et al. 2021

Ind. Eng. Chem. Res.

With the high-frequency development of highspeed communication electronic devices, excellently adhesive materials with low dielectric constant and ultralow dielectric loss have been highlighted. However, intrinsically strong adhesive materials (e.g., epoxy) with numerous polar functional groups disappointingly deteriorate their high-frequency dielectric properties. Herein, a double cross-linked network of maleic-anhydride polybutadiene−amino-terminated polyimide oligomers (MAPB-PIO) is synthesized, and then a novel sandwich-layered dielectric film (MAPB-PIO/polytetrafluoroethylene (PTFE)/MAPB-PIO) is prepared through double-sided coating. The MAPB-PIO/PTFE/ MAPB-PIO film exhibits low dielectric constant (D k = 1.9929) and ultralow dielectric loss (D f = 0.0012) at 10 GHz. Meanwhile, the interface peel strength reaches 0.912 N/mm. Additionally, the MAPB-PIO/PTFE/MAPB-PIO film is successfully applied to manufacture a flexible printed circuit board (PCB) and shows an outstanding high-frequency signal transmission capability; i.e., signal loss is 26.45 dB at 18 GHz, which is only 43% of the commercially available epoxy resin PCB. All results indicate that the flexible MAPB-PIO/PTFE/MAPB-PIO film is highly promising for applications in next-generation flexible electronics and radiofrequency devices, especially in the millimeter wave field.

Section: Resultsmentioning

confidence: 96%

“…Generally, the electron transition was from the HOMO of the donor to the LUMO of the acceptor. The energy gap (Δ E ) should be calculated by Δ E = E LUMO – E HOMO . It should be noted that the E HUMO values of ODA-ODPA and butadiene were close, implying that their HUMOs were prone to overlap, leading to a strong interaction.…”

Section: Resultsmentioning

confidence: 99%

Sandwich-Layered Dielectric Film with Intrinsically Excellent Adhesion, Low Dielectric Constant, and Ultralow Dielectric Loss for a High-Frequency Flexible Printed Circuit

Liu

et al. 2021

Ind. Eng. Chem. Res.

“…The throwing power ( TP ), a crucial indicator to characterize the thickness uniformity of the copper coating in the THs, was obtained according to the cross‐section images [46–48] . The throwing power ( TP ) value was calculated by the Equation (5).…”

Section: Methodsmentioning

confidence: 99%

“…The throwing power (TP), a crucial indicator to characterize the thickness uniformity of the copper coating in the THs, was obtained according to the cross-section images. [46][47][48] The throwing power (TP) value was calculated by the Equation ( 5). The H a , H b , H c , H d , H e and H f in the formula were the electroplated copper coating thickness presented in the Figure 8.…”

Section: Electroplating Experimentsmentioning

confidence: 99%

Toward Preeminent Throwing Power from a Novel Alkaline Copper Electronic Electroplating Bath with Composite Coordination Agents

Jin

Yang

et al. 2022

ChemElectroChem

In this work, an electronic copper electroplating bath with low copper ion concentration and preeminent throwing power in through hole (TH) thickening of the printed circuit board (PCB) was successfully developed. Based upon the weak alkaline bath containing the composite complexants of citrate (Cit) and ethylenediamine (En), their synergistic effects on the preeminent bath throwing power were carefully investigated and theoretically proved. The UV‐vis spectroscopy results illustrated that En exhibited a stronger coordination ability with Cu (II) ion than citrate, and the stoichiometric coordination ratio between En and Cu (II) ion was 2 : 1. The linear sweep voltammetry (LSV) results showed that the electro‐reduction peak potential of Cit−Cu coordination ion was −0.55 V (vs. Hg/HgO), whereas that of En−Cu ion was at a more negative potential of −0.82 V. The in situ Fourier transform infrared (FTIR) spectroscopy revealed that the adsorptions of the Cit−Cu and En−Cu coordination ions were potential dependent on the copper electrode. The Cit−Cu coordination ion was easily adsorbed at the interior sites of through holes with lower over‐potential to promote the growth of copper coating. Moreover, the En−Cu coordination ion adsorbed preferably on the surface and the edge of through hole for its higher electro‐reduction overpotential, to hinder the germinating of copper nuclear. The cross‐section observation of optical microscope proved that the throwing power of novel copper electroplating bath behaved surpassingly, up to 105.8 %.

“…The surface evenness of the copper interconnects structure is important for achieving low transmission loss at high frequency. Now, copper electrodeposition technology of copper interconnected structure is based on the synergistic mechanism of organic additives to achieve the plating of interconnects structure in the acid copper electroplating system [3,4]. The organic additives can be mainly divided into three types, which are organic accelerators, inhibitors, and levelers [5,6].…”

Section: Introductionmentioning

confidence: 99%

Influence of polyethylene glycol inhibitors on properties of electroplated copper layer

Xiang

Qin

et al. 2022

J. Phys.: Conf. Ser.

Inhibitor is one of the important additive components in electrodeposited copper. As a common inhibitor, the concentration of PEG8000 has an important effect on electrodeposited copper. In this article, different concentrations of polyethylene glycol-based organic additives were added to the acidic electrolyte, and their effects on the electrochemical behavior of copper electrodeposition were investigated by galvanostatic test, cathodic polarization curve test, and cyclic voltammetry test. In addition, the surface morphology and crystallographic orientation of the obtained copper layers were analyzed by SEM and XRD. The results show that with the increase of PEG8000 concentration in the electroplating solution system, the inhibitory effect of PEG8000 on electroplating copper becomes stronger, and the copper surface density obtained by electroplating is better.