树脂塞孔研磨过程中镀覆孔拐角露铜的探究

文章通过对树脂塞孔和树脂研磨的设计、制作和过程管控等方面进行优化,改善树脂塞孔板的金属化孔口铜厚不足及基材缺陷问题,防止后续镀铜后镀层分离报废产生,从而改善产品品质,提高客户满意度.     

Thermodynamic analysis of free cyanide determination by silver nitrate titration in copper bearing solutions

The present study is a thermodynamic approach to explain the titration of free cyanide by silver nitrate in cyanide solutions containing copper. When copper is present in cyanide solutions, the visual determination of the endpoint of the titration leads to an overestimation of the free cyanide concentration that can be up to 56% when the indicator is potassium iodide, or up to 121% for rhodanine. Four alternatives were evaluated to detect the endpoint of the titration: visual detection with potassium iodide, visual detection with rhodanine, potentiometric endpoint detection with silver electrode and derivative curve of the potentiometric titration. The last two methods showed the best results (the smallest overestimation, reaching no more than 8%). A comparison between the titration graphs and the equilibrium composition diagrams allows the understanding of the overestimation, and permits the qualitative and quantitative determination of all the copper cyanide species that are being titrated with silver nitrate.

Cette étude est une approche thermodynamique ayant pour but d’expliquer le titrage au nitrate d’argent du cyanure libre de solutions de cyanure contenant du cuivre. Lorsque le cuivre est présent dans les solutions de cyanure, la détermination visuelle du point final du titrage mène à une surestimation de la concentration du cyanure libre, qui peut aller jusqu’à 56% lorsque l’indicateur est l’iodure de potassium, ou jusqu’à 121% pour la rhodanine. On a évalué quatre solutions possibles de détection du point final du titrage: détection visuelle avec l’iodure de potassium, détection visuelle avec la rhodanine, détection potentiométrique du point final avec électrode d’argent et courbe dérivée du titrage potentiométrique. Les deux dernières méthodes ont montré les meilleurs résultats (surestimation la plus petite, n’atteignant pas plus de 8%). Une comparaison entre les graphes de titrage et les diagrammes d’équilibre de la composition permet de comprendre la surestimation et permet la détermination qualitative et quantitative de toutes les espèces du cyanure de cuivre qui sont titrées avec le nitrate d’argent.     

Extractive metals from metallic powders recovered from waste printed circuit boards

Leaching behaviours of metallic powders were investigated using electrically generated chlorine at the anode chamber containing sulphuric acid solution, NaCl and CuSO₄. Various parameters, which included the solid/liquid ratio, current density, concentration of NaCl, CuSO₄, and H₂SO₄, leaching temperature, particle size, and stirring speed, were studied to understand the mechanism of leaching metallic powders. The capability of dissolved metallic powders increased with the increase in all parameters except the solid/liquid ratio. Leaching metallic powders were transport-controlled with a low activation energy of 14·7 kJ mol^?1. The dissolved copper could be transferred from the anodic chamber to the middle chamber by solvent extraction technology. In the electric field, copper ions are transferred from the middle chamber to the cathodic chamber through a cation exchange membrane (CEM) and electrodeposited to form copper foils. The tensile strength and elongation percentage of 65 μm-thick copper foils were 276 Mpa and 10·66%, respectively. The utilisation of metallic powders recovered from waste PCBs (WPCBs) could produce high-performance copper foil.

On a examiné le comportement de lixiviation de poudres métalliques en utilisant du chlore engendré par électricité dans la chambre de l’anode contenant une solution d’acide sulfurique, du NaCl et du CuSO₄. On a étudié une variété de paramètres, incluant le rapport solide à liquide, la densité de courant, la concentration de NaCl, de CuSO₄ et d’H₂SO₄, la température de lixiviation, la taille de particule et la vitesse d’agitation, afin de comprendre le mécanisme de lixiviation des poudres métalliques. La capacité des poudres métalliques dissoutes augmentait avec l’augmentation de tous les paramètres, sauf le rapport solide à liquide. Les poudres métalliques de lixiviation étaient contrôlées par le transport, avec une faible énergie d’activation de 14·7 kJ/mol. On pouvait transférer le cuivre dissous de la chambre anodique à la chambre du milieu au moyen de la technologie d’extraction par solvant. Dans un champ électrique, les ions de cuivre étaient transférés de la chambre du milieu à la chambre cathodique par une membrane d’échange de cation et étaient déposés par galvanoplastie pour former des feuilles de cuivre. La résistance à la traction et le pourcent d’élongation de feuilles de cuivre de 65 μm d’épaisseur étaient respectivement de 276 MPa et de 10·66%. Les poudres métalliques récupérées de cartes de circuit imprimé de rebut pourraient produire une feuille de cuivre à haute performance.     

Direct selective leaching of chalcopyrite concentrate

The ammonium persulphate (APS) leaching of chalcopyrite concentrate in the presence of ammonium carbonate was studied. The effects of ammonium carbonate concentration, APS concentration, leaching time, leaching temperature, solid/liquid ratio and stirring speed were investigated. Optimum leaching conditions were found as follows: APS concentration is 200 g L^?1; ammonium carbonate concentration is 200 g L^?1; leaching time is 180 min; leaching temperature is 60°C; solid/liquid ratio is 0·04 g mL^?1; and stirring speed is 400 rev min^?1. Under these conditions, copper extraction yield was obtained at about 72%. Furthermore, iron extraction yield decreased with increasing ammonium carbonate concentration and iron did not pass into solution under this condition. X-ray and SEM analysis also supported these results. It was determined that the copper extraction results were satisfactory by way of all experiments were performed under atmospheric conditions (i.e. low temperature and atmospheric pressure) and achieved selective copper leaching from chalcopyrite concentrate.

On a étudié la lixiviation au persulfate d’ammonium (APS) du concentré de chalcopyrite en présence de carbonate d’ammonium. On a examiné l’effet de la concentration du carbonate d’ammonium, de la concentration d’APS, de la durée et de la température de lixiviation, du rapport solide-liquide et de la vitesse d’agitation. Les conditions optimales de lixiviation suivent: concentration d’APS?=?200 g L^?1; concentration de carbonate d’ammonium?=?200 g L^?1; durée de lixiviation?=?180 min; température de lixiviation?=?60°C; rapport solide-liquide?=?0·04 g mL^?1; et vitesse d’agitation?=?400 rpm. Avec ces conditions, le rendement d’extraction du cuivre était d’environ 72%. De plus, le rendement d’extraction du fer diminuait avec l’augmentation de la concentration de carbonate d’ammonium, qui empêchait également le fer de passer en solution. L’analyse aux rayons x et au SEM supportait également ces résultats. Grâce à toutes les expériences effectuées en conditions atmosphériques (c’est-à-dire à basse température et à pression atmosphérique), on a déterminé que les résultats d’extraction du cuivre étaient satisfaisants et qu’on obtenait une lixiviation sélective du cuivre à partir du concentré de chalcopyrite.     

Electrochemical and transport properties of ethaline containing copper and tin chloride

Electrochemical and transport properties were measured for hydrated chloride salts of copper and tin in ethaline, which is a 1∶2 ratio of choline chloride and ethylene glycol. Density, viscosity and conductivity for ethaline melts with different salt concentrations have been measured for temperatures between 293 and 328 K. The change in formal potential with changing metal ion concentration has been determined to evaluate changing speciation in the ionic liquid. Cyclic voltammetry has been carried out to ascertain the reduction potential and diffusion coefficient of the reacting species. For pure ethaline the density was found to decrease by <5% with increase in temperature. On the other hand, the viscosity was found to decrease and conductivity was found to increase by 65% over the same temperature range. The inclusion of metal salts in ethaline had negligible effect on these parameters. Potential measurements showed that copper was reduced through a two-step mechanism and Sn was reduced via a two electron transfer route. The diffusion coefficient values for Cu²⁺ and Sn²⁺ species were 1·22×10^?11 and 1·96×10^?11 m² s^?1 respectively.     

Adsorption of O-isopropyl-N-ethyl thionocarbamate on Cu sulfide ore minerals

The adsorption of the flotation collector O-isopropyl-N-ethyl thionocarbamate on air-exposed Cu metal, cuprite, chalcocite, covellite, cubanite, chalcopyrite, bornite and pyrite at pH ∼6 has been investigated primarily by X-ray photoelectron spectroscopy. It was found that Cu^I oxide and sulfide surfaces conditioned in the collector solution were hydrophobic, regardless of whether the collector adsorbed as the anion (IPETC⁻), in protonated form (HIPETC), or as multilayer CuIPETC patches. The Cu^I native oxide layer on the metal was largely unaffected by the adsorbed collector. For surfaces at which chemisorption occurred, interaction of the S in the collector was directly with Cu in the metal or mineral surface, rather than via O. Apart from chalcocite, the main species adsorbed from the collector solution on to Cu^I oxide surfaces were different from those adsorbed on the sulfide minerals, in that the N was predominantly deprotonated in the former and protonated in the latter. On chalcocite, comparable amounts of IPETC and HIPETC were adsorbed. Adsorbed HIPETC was in good electrical contact with the surface of cubanite, chalcopyrite and bornite, presumably because of direct interaction with the mineral rather than adsorption on top of chemisorbed IPETC or FeOOH. Collector coverage of the Cu minerals correlated with the availability of CuOH_surf with which HIPETC could react. Coverage by collector adsorbed as HIPETC on pyrite surfaces was low, but not negligible, nevertheless conditioned abraded pyrite surfaces were not obviously hydrophobic.     

铜尾矿的一种新型干堆技术

首先介绍了我国铜尾矿的现状,并对现有铜尾矿的处理方法作了简要总结。针对目前铜尾矿处理方法中存在的问题,以实现铜尾矿处理为目标,首先使粗细颗粒分级,再分别进行浓缩脱水的方法,确定了在目前条件下一种较为合理的铜尾矿新型干堆技术。同时,对该干堆技术中采用的主要设备作了简单描述,并对该技术与其他干堆技术在适用范围、技术、经济等方面进行了对比。经实践证明,通过该技术处理的铜尾矿,粗粒部分含水量可控制在18%以下,细粒部分含水量控制在23%以下,可直接实现皮带输送或汽车运输,完全达到了干堆的要求。与常规处理方法相比,具有设备一次性投资少,干堆效果好,运行费用低,设备维修维护简单等明显优点,是目前为止一种技术上可行、经济性上合理的尾矿干堆技术。该技术对其他类型的尾矿具有借鉴意义。     

Thermal characterisation of ceramic/metal joining techniques for fusion applications using X-ray tomography

This work investigates the thermal performance of four novel CFC–Cu joining techniques. Two involve direct casting and brazing of Cu onto a chromium modified CFC surface, the other two pre-coat a brazing alloy with chromium using galvanisation and sputtering processes. The chromium carbide layer at the interface has been shown to improve adhesion. Thermal conductivity across the join interface was measured by laser flash analysis. X-ray tomography was performed to investigate micro-structures that might influence the thermal behaviour. It was found that thermal conductivity varied by up to 72%. Quantification of the X-ray tomography data showed that the dominant feature in reducing thermal conductivity was the lateral spread of voids at the interface. Correlations were made to estimate the extent of this effect.     

0.13μm铜互连工艺鼓包状缺陷问题的解决

传统集成电路制造工艺主要采用铝作为金属互连材料,但是随着晶体管尺寸越来越小,在0.13μm及以上制程中,一般采用铜大马士革互连工艺来提高器件的可靠性。铜互连工艺中需要用氮化硅作为穿孔图形蚀刻的阻挡层,由于氮化硅材质具有很强的应力,再加上制程中的热反应和蚀刻效应就会造成氮化硅层从界面掀起从而形成一种鼓包状缺陷(bubble defect)。文章通过调整并控制铜金属连线层间氧化电介质层的蚀刻速率,改变有机介质层(BARC)的沉积方法,以及改进产品的电路设计的检验规则,从而解决鼓包状缺陷的产生,降低产品芯片的报废率,提高产品的良率。     

Electrodeposition of cobalt based ferro-magnetic metal nanowires in polycarbonate films with cylindrical nanochannels fabricated by heavy-ion-track etching

Polycarbonate films of thickness 30 μm were irradiated with heavy ions by applying a flux of 10⁸ ions cm⁻² to produce straight tracks perpendicular to the film surface. The tracks were preferentially etched in 6 M aqueous solution of sodium hydroxide to prepare cylindrical nanochannels. The channel diameters were tuned between 200 and 600 nm by varying the etching time. Co₈₁Cu₁₉ alloy nanowires were electrodeposited potentiostatically, while Co/Cu multilayered nanowires, consisting of alternating Co and Cu layers with thickness 10 nm, were synthesized by means of a pulse plating technique in channels of length 30 μm and diameter 200 nm. Co₈₁Cu₁₉ alloy nanowires showed an anisotropic magnetoresistance effect of 0.6%, and the giant magnetoresistance of Co/Cu multilayered nanowires reached up to 8.0%.