Improving interfacial adhesion between copper foil and resin using amino acid in printed circuit board industry

The corrosion inhibitor of nitrogen-containing amino acid histidine (His) has been applied in brown oxidation solutions and the relationships between brown oxidation solutions with the various concentrations of His and the adhesion strength of copper/resin laminates have been systematically studied by various testing techniques, including electrochemical impedance spectroscopy (EIS), peeling strength and field emission scanning electronic microscope. The result obtained from EIS suggested that His exhibited excellent anti-corrosive performance which contributed to a higher stability of the organic metallic film post brown oxidation process treatment. The roughness surface like honeycomb structure was gained and peel strength of the Cu/resin laminates was raised up to 0.71 kg/cm by altering the concentration of His in brown oxidation solutions. Moreover, theoretical calculations manifested that the studied inhibitor was almost adsorbed in parallel on the copper surface and X-ray photoelectron spectroscopy (XPS) declared that the value of adhesion strength was related to the surface chemistry of copper foil and resins after the lamination process which may attribute to chemical reactions at the copper/resin interface.     

Obtaining of high surface roughness copper deposits by electroless plating technique

The use of pyridine-2,6-dicarboxylic and 4-hydroxypyridine-2,6-dicarboxylic acids as copper(II) ligands in formaldehyde-containing alkaline electroless copper plating solutions allowed to obtain copper layers with extremely high surface roughness factor reaching approximately 120. The Cu deposits of higher surface area were formed at highly negative open-circuit (mixed) potentials; the correlation between copper electrode overpotential and roughness of the deposit was found and discussed. The copper films obtained demonstrate a high electrocatalytic activity in anodic formaldehyde oxidation process, the oxidation rate reaches 40 mA cm⁻² and exceeds considerably that for other copper surfaces.     

氧化剂对铝栅化学机械抛光的影响

氧化剂作为抛光液的组成成分,在铝栅化学机械抛光(CMP)中起到直接影响去除速率和表面粗糙度的重要作用。本文研究了氧化剂浓度对去除速率、表面粗糙度、电化学特性的影响,采用原子力显微镜和CHI600E电化学工作站,分别测量了材料的表面粗糙度和腐蚀电位。结果表明,去除速率与氧化剂浓度有关,表面粗糙度与通过氧化反应生成的氧化层有关,当氧化剂达到15mL/L时,去除速率可达到1700 nm/min,表面粗糙度为4.6 nm。     

Electrochemical investigation of copper–DTPI interactions

The electrochemical behavior of copper in the absence and presence of a dithiophosphinate type collector, sodium diisobuthyldithiophosphinate (NaDTPI), was determined to investigate the interactions between a copper surface and NaDTPI as a function of pulp potential (Eh) and pH. The electrochemical studies were performed by Cyclic Voltammetry (CV) in the −355 to +1550 mV (SHE) potential range and at different pHs from slightly acidic to strongly alkaline conditions. The electrochemical studies were carried out for copper and DTPI alone as well as with DTPI added copper system. DTPI addition had considerable effects on the electrochemical behavior of copper. CuDTPI formation was the main reaction at all pHs through a mixed mechanism and oxidation of the copper surface was followed by a chemical reaction between copper and DTPI ions. Formation of a cupric metal-collector complex, Cu(DTPI)₂, was observed only in acidic conditions in the form of an unstable surface compound.     

Evaluation of the surface roughness of microporous Ni–Zn–P electrodes by in situ methods

The surface roughness of porous Ni–Zn–P electrodes was studied in 1 M NaOH using in situ electrochemical techniques: ratio of the polarization current densities, electrochemical impedance spectroscopy, cyclic voltammetry, coulometric oxidation of the surface, and a new technique of a CO molecular probe. The obtained surface roughness was about 5.5 × 10³. Good agreement was observed between the results obtained by all these techniques.     

2A12铝合金冷喷铜涂层的组织与性能

铝合金是常用的导电类零部件基材,工程上一般采用电镀铜或热喷涂铜技术在铝合金零部件表面制备单质铜涂层提高其导电性,但电镀铜层与基体结合不稳定,热喷涂铜涂层存在粗糙度大、易氧化的问题。以冷喷涂技术为手段在2A12铝合金基体上制备单质铜涂层,采用显微镜、扫描电镜、X-射线衍射、表面粗糙度测量仪、显微硬度计和划痕试验机进行涂层组织与性能研究。结果表明,涂层氧化率较低,粗糙度与电弧喷铜涂层相比明显减小,涂层组织过渡良好,未发现明显的疏松与空洞,结合力高于电弧喷涂涂层,电阻率约小于电弧喷涂。     

Etablissement de diagrammes tension-pH cinetiques du cuivre en milieu de chlorures

The electrochemical behaviour of a copper electrode in chloride solutions was studied under strictly controlled hydrodynamic conditions with a rotating disc electrode and for large NaCl and CuCl concentration variations. The results are presented as kinetic potential-pH curves for oxidation of copper and for oxidation of the solutions on a platinum electrode.     

Copper (hydr)oxide modified copper electrode for electrocatalytic oxidation of hydrazine in alkaline media

Stable copper (hydr)oxide modified copper electrode was prepared by cyclic voltammetry in 0.1 M NaOH solution in the potential range of −300 to 800 mV. In the first cycle the oxidation peaks of copper were observed but in the second and next cycles, they were omitted and a clean background was obtained. This indicates that an irreversible electrochemical transformation has been achieved during the first cycle and a stable layer of hydr(oxide) formed on the surface of the copper electrode. This layer protects the electrode from corrosion. This electrode can be used for electrochemical studies in the potential range of −300 to 800 mV without any interfering effects by the oxidation peaks of copper. The modified electrode was used for electrocatalytic oxidation of hydrazine. Results showed that on the bare copper electrode the oxidation peak of 10 mM hydrazine appear at 380 mV while on the copper (hydr)oxide modified copper electrode, it appear at 260 mV. About 120 mV negative shift of the peak potential indicated the catalytic activity of (hydr)oxide layer for hydrazine. The kinetic parameters were investigated by using cyclic voltammetry and chronoamperometry.     

Structural and electrochemical features of 3D nanoporous platinum electrodes

The morphologies, roughness factors, and thicknesses of 3D nanoporous Pt (3D-npPt) films were investigated in terms of electroplating conditions. The electrochemical behaviors of 3D-npPt films with regard to electrochemical glucose oxidation, O₂ reduction, and H₂O₂ reduction were investigated as a function of roughness factors (Rf). Close comparison of glucose oxidation on 3D-npPt and 1D nanoporous Pt (1D-npPt) showed that the overall electrode activity of 3D-npPt is significantly higher than that of 1D-npPt. Electrochemical impedance analysis based on transmission line theory confirmed a substantially low pore resistance of 3D-npPt, which may account for the superior electrode response of this material.     

An electrochemical approach to total organic carbon control in printed circuit board copper sulfate plating baths Part I: Anode performances

An electrochemical approach to decreasing high levels of total organic carbon (TOC) in printed circuit board (PCB) copper sulfate plating baths has been investigated. The organic contaminants build-up over the course of pattern plating of PCBs, and at high concentrations they interfere with the quality of the plated copper. The electrochemical approach involves destroying the organic contaminants using electrochemical oxidation. Various anode materials (glassy carbon, lead, lead dioxide, platinum, iridium dioxide and doped tin dioxide) were screened for this application. Some corrosion data is presented for these anodes and their performance for TOC removal at various current densities has been roughly quantified using an apparent first order rate constant. The three best performing anode materials gave increasing oxidation rates going from platinum to doped tin dioxide to lead dioxide, unfortunately anode stability decreased in the same order.     

Anisotropically conducting films consisting of sub-micron copper wires in the ion track membranes of poly(ethylene terephthalate)

Ion track membranes of poly(ethylene terephthalate) (PET) are applied to the production of anisotropically conducting films possessing copper wires of less than sub-micron in diameter. The membranes possessing cylindrical pores of 1.9 μm and 200 nm in diameter were prepared by irradiation of ¹²⁹Xe²³⁺ ion beams followed by etching in an aqueous NaOH. Copper wires were deposited into the pores by electrochemical plating in aqueous copper sulfate solution to prepare the PET/Cu hybrid membranes. The copper wires with 1.9 μm in diameter showed wavelike surface roughness, resulting from the roughness of the pore side wall, whereas the copper wires with 200 nm in diameter showed smooth surfaces. The resistances of the membranes measured by a four terminal resistance method are in good agreement with the calculated values, indicating that the hybrid membranes possess conductivity perpendicular to the membrane surfaces but not parallel to the surfaces.     

浸铜液中丙烯硫脲和Fe^2＋离子浓度的快速测定

根据铂电极上的丙烯硫脲对铜电沉积过程的阻化效应和Ｆｅ＾２＋离子的电化学氧化特性，用ＤＺ－１Ｂ型电镀添加剂测定仪快速测定浸铜液中的丙烯硫脲和Ｆｅ＾２＋离子浓度。     

Effect of the microstructure of copper oxide on the adhesion behavior of epoxy/copper leadframe joints

The thermal oxidation of copper leadframe was carried out at 175°C and the adhesion behavior of the epoxy/copper leadframe joint was analyzed by investigating the microstructure changes of copper oxide with the thermal oxidation time of copper. The peel strength increased sharply at an early stage of oxidation (~20 min) followed by a slight increase. After further oxidation (120 min), the peel strength showed a slight decrease. The contact angles of water and diiodomethane decreased sharply at an early stage of oxidation with negligible change afterwards. As the oxidation time increased, X-ray photoelectron spectroscopy (XPS) results revealed that the chemical composition of copper oxide had changed (Cu/Cu₂O → Cu₂O → CuO); this change improved the wettability of the copper surface, which affected the peel strength. Increase of the surface roughness of copper oxide, investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), causes the epoxy resin and copper oxide to undergo mechanical interlocking, which increases the peel strength. Failure analysis by SEM and XPS indicated that failure was largely in the copper oxide, and the amount of copper oxide on the peeled epoxy increased as the oxidation time increased, due to the weak mechanical strength of the oxide layer. However, a small portion of the epoxy resin was also fractured during the failure process, regardless of the oxidation time. Consequently, fracture proceeded mainly in the copper oxide close to the epoxy resin/copper oxide interface.     

铜表面物理化学有序度对蒸汽冷凝特性的影响

研究了经不同粒度砂纸研磨后不同粗糙度纯铜表面的润湿性和蒸汽冷凝性能,分析了表面物理粗糙度和氧化引起的表面化学成分异质性对润湿性和冷凝传热性能的影响规律。结果表明,当铜表面粗糙度小于0.15 μm,增大粗糙度有利于增大接触角,而当粗糙度增大到0.15 μm后,继续增大粗糙度反而会减小其表面接触角。铜表面氧化后造成的化学成分异质性有利于增大接触角。表面微观结构和化学成分异质性的共同作用决定了铜表面的润湿性与蒸汽在其表面的冷凝模式。当粗糙度为0.15 μm左右时,氧化后铜表面表现出最佳的滴状冷凝状态,其冷凝传热系数达到Nusselt理论模型的3.5倍左右。但是表面粗糙结构同时也会增大液滴在金属表面的运动阻力,对冷凝传热性能产生不利影响。     

对羟基苯甲酸自组装膜对铜的缓蚀作用

利用自组装技术将对羟基苯甲酸在铜表面形成自组装单分子膜,利用电化学阻抗谱和极化曲线研究了自组装膜对铜的缓蚀作用及其吸附行为。结果表明,对羟基苯甲酸分子易在铜表面形成稳定的自组装单分子膜,该膜抑制了铜的阳极氧化过程,改变了电极表面的双电层结构,固/液界面双电层电容明显降低,有良好的缓蚀效果。研究结果还表明,对羟基苯甲酸在铜表面的吸附行为符合Langmuir吸附等温式,吸附机理是典型的物理吸附。     

挠性印刷电路板用超低轮廓铜箔的表面处理工艺

研究了挠性印制电路板(FPC)用超低轮廓(VLP)电解铜箔的表面处理工艺.在硫酸铜与硫酸的混合电解液中,以连续旋转鼓状钛筒为阴极,在50～80A/dm<'2>的电流密度下电沉积得到12μm厚的铜箔,再以(20±0.1)m/min的速度对铜箔进行表面处理:在其光面进行分形电沉积铜,然后电沉积纳米锌镍合金,再经过三价铬钝化...     

粘胶基碳纤维连续式电化学氧化表面处理（1）：碳纤维表面的物理 …

本文报道了用连续式电化学氧化表面处理粘胶基碳纤维表面,并测定了处理后碳纤维的单丝强度,表面浸润性,表面活性官能团含量及表面形貌等表面物理化学性能。结果表明：粘胶基碳纤维经电化学氧化表面处理可以有效地在表面主生活性官能团和提高表面粗糙度,从而有效地提高表面润湿性,但经处理后单丝强度较易下降,因此需精确控制处理的条件。     

Simultaneous recovery of heavy metals and degradation of organic species – copper and ethylenediaminetetra‐acetic acid (EDTA)

In mixed industrial effluent the presence of metal ions can retard the destruction of organic contaminants and the efficiency of recovery of metal is reduced by the presence of the organic species. Results are presented for a copper–ethylenediaminetetra‐acetic acid (EDTA) system in which both effects occur. An electrochemical cell alone can be used to recover copper in pH range 1.5–4.5 but is not capable of achieving complete mineralisation of EDTA by anodic oxidation. A photolytic cell alone can achieve the destruction of EDTA at pH 3.5 but leaves copper in solution. A combined photolytic–electrochemical system using an activated carbon concentrator cathode achieves the rapid simultaneous destruction of EDTA and recovery of copper. © 2000 Society of Chemical Industry     

Investigation of the Metal–Oxide Buried Interfacial Zone with Linear Sweep Voltammetry

Interest in copper as a technologically important material needs to be met with greater understanding of the fundamental chemical reactions of copper. In particular, there is still a lack of universal agreement on the oxidation process of bulk copper and thin copper films. In this study, the authors demonstrate the use of linear sweep voltammetry (LSV) to study buried structures in the oxide layers on copper. In particular, LSV can be used to detect reactions at buried interfaces. It is also emphasized that surface scientists should recognize Cu₃O₂ and the decomposition of copper oxides at the metal–oxide interface in new studies on copper oxidation and in interpreting already existing copper oxidation data. The two key parameters that drive oxide growth and decomposition are demonstrated to be oxygen activity and the free energies of formation of the oxides (per mole of oxide ion). The complex nature of the oxidation of copper, as well as other metals and alloys, can be described qualitatively using the Modified Cabrera–Mott (C–M) Model. Surface studies of oxidation of metals and alloys need to be supported and complemented by other techniques such as chemical or electrochemical methods.     

Electrodeposition of copper on thermally oxidized 316 L stainless steel substrates

The effect of thermal oxidation of 316 L stainless steel cathode blanks used in copper electrodeposition was studied. Current and potential step experiments were performed to evaluate electrochemical changes caused by the oxidation treatments. SEM and AES were used to characterize the stainless steel substrates and the deposited copper films. Particular emphasis was given to the initial stages of copper nucleation and growth. The copper electrocrystallization process was strongly influenced by the temperature employed in oxidizing the stainless steel. Dense, uniform and fine copper nuclei were obtained on the stainless steel substrate oxidized in air at 200°C and 300°C for 3h. The copper nucleation density and uniformity decreased considerably on substrates treated at 500°C and 600°C. Attempts were made to identify changes in the mechanism of copper nucleation on the various oxidized stainless steel substrates using models developed by Thirsk and Harrison.