Showing papers on "Copper plating published in 2012"

Direct Writing Patterns for Electroless Plated Copper Thin Film on Plastic Substrates

Abstract: A simple and efficient method is developed to create conductive copper thin films on polymer surfaces. Instead of regular palladium colloid inks, micropatterns of silver nitrate inks, which serve as an activating agent for copper plating, were printed and dried on flexible plastic substrates. The printed plastic sheets were then immersed in an electroless copper plating bath at 55 °C for 2 min to create copper thin films on the printed patterns. The prepared copper films have an electrical conductivity as high as 83% of bulk copper and show good adhesion on PET or PI substrates.

Direct electroless nickel-boron plating on AZ91D magnesium alloy

Abstract: A Ni–B coating was electroless-deposited directly on acetic acid pickled AZ91D. The plating rate was found to be influenced by pH, temperature, and bath composition. The electroless Ni–B plating exhibits a uniform surface and an amorphous structure. Polarization curve and electrochemical impedance spectroscopy measurements in 3.5 wt.% sodium chloride aqueous solution suggest that the plating can protect the magnesium alloy substrate from corrosion attack. It is proposed that different deposition reactions dominate in different stages of the plating process.

Potential Oscillations in Galvanostatic Cu Electrodeposition: Antagonistic and Synergistic Effects among SPS, Chloride, and Suppressor Additives

Abstract: Polymerizates of imidazole and epichlorohydrin (Imep) serve as one of the benchmarks for today's chemistry development of leveler additives in context of the industrial copper Damascene process. We therefore studied the synergistic and antagonistic interplay of the Imep polymer with other additives, commonly present in copper plating baths used for the state-of-the-art IC manufacturing. Characteristic oscillations in the applied electrode potential appear in galvanostatic copper electrodeposition when Imep is used in combination with SPS (bis(sodium sulfopropyl) disulfide). We identified the reversible Cu(I) coordination chemistry of the Imep polymer as a second prospective driving force beyond interfacial anion/cation pairing toward the formation of such suppressor/leveler ensembles at the interface. OH groups of the pristine Imep polymer coordinate with H2O-Cu(I)-MPS units (primary effect) that appear as side products of the copper electrodeposition in the presence of SPS. The latter transforms during c...

Influence of Copper Plating on Electromagnetic and Temperature Fields in a High-Speed Permanent-Magnet Generator

Abstract: In a high-speed permanent-magnet generator (HSPMG), an alloy sleeve is often used to prevent damage to rotor magnets caused by the large rotational centrifugal forces. However, eddy-current losses appearing in the sleeve increase the generator working temperature, which may reduce the generator performance and even cause thermal demagnetization of the magnets. Thus, a sleeve scheme designed with low eddy current losses is necessary, and a rotor structure with copper plating is presented in this paper. The two-dimensional mathematical model of a 117 kW, 60 000 rpm HSPMG is established, and the electromagnetic field in the generator is calculated using the finite element method. The results show the effectiveness of the copper plating in reducing the eddy current losses in the rotor, and the influences of the sleeve thickness and the copper layer thickness on rotor eddy current losses are analyzed. Using the fluid-thermal coupling method, the temperature distribution of the generator with different copper layer thicknesses is comparatively analyzed based on the theories of fluid mechanics and heat transfer. The relationship between the temperature and the copper layer thickness is obtained, and finally the temperature of the permanent magnets, which is the part most seriously affected by the temperature, is given with different copper layer thicknesses. The obtained conclusions may provide useful reference for the design and research of HSPMG.

Copper foil with carrier

Abstract: Provided is a copper foil for a printed wiring board including a roughened layer on at least one surface thereof. In the roughened layer, the average diameter D 1 at the particle bottom being apart from the bottom of each particle by 10% of the particle length is 0.2 to 1.0 μm, and the ratio L 1 /D 1 of the particle length L 1 to the average diameter D 1 at the particle bottom is 15 or less. In the copper foil for printed wiring board, when a copper foil for printed wiring having a roughened layer is laminated to a resin and then the copper layer is removed by etching, the sum of areas of holes accounting for the resin roughened surface having unevenness is 20% or more. The present invention involves the development of a copper foil for a semiconductor package substrate that can avoid circuit erosion without causing deterioration in other properties of the copper foil. In particular, an object of the present invention is to provide a copper foil for a printed wiring board and a method of producing the copper foil, in which the adhesion strength between the copper foil and the resin can be enhanced by improvement of the roughened layer of the copper foil.

Role of additives in electroless copper plating using hypophosphite as reducing agent

Abstract: In electroless copper plating baths using hypophosphite as the reducing agent, nickel ions was used to catalyze hypophosphite oxidation. However, the color of the copper deposits was dark or brown and the electrical resistivity was much higher than that obtained from formaldehyde baths. Polyethylene glycol (PEG) and K 4 Fe(CN) 6 were used to improve the microstructure and properties of copper deposits obtained from electroless copper plating bath using hypophosphite as the reducing agent. The effects of PEG concentration on the deposition rate, the microstructure, morphology and electrical resistivity of the copper deposits, and the electrochemical reactions of hypophosphite (oxidation) and cupric ion (reduction) were investigated. The traces of hydrogen escaping from the deposits surface disappeared and the color of the copper deposits changed from dark-brown to dark red when the PEG concentration was 1.67 × 10 − 5 M or more. The deposition rate increased and the electrical resistivity of the copper deposits decreased slightly with the addition of PEG to the plating solution. The electrical resistivity of copper deposits decreased to 2.85 μΩ cm with 1.67 × 10 − 5 M PEG and 4.70 × 10 − 6 M K 4 Fe(CN) 6 in the bath. Larger grain size and higher (220) plane orientation were obtained with the increase of PEG concentration in the bath. The electrochemical current–voltage results showed that PEG accelerated the catalytic oxidation of hypophosphite at active nickel sites and had little effect on the reduction reaction of cupric ions on the deposit surface by adsorption on the electrode.

Alkaline non-cyanide plating solution for copper-plating used on iron and steel base and preparation method thereof

Abstract: An alkaline non-cyanide plating solution for copper-plating used on iron and steel base and a preparation method thereof relate to a kind of plating solution. The invention provides the alkaline non-cyanide plating solution for copper-plating used on iron and steel base and the preparation method thereof. The plating solution comprises the following components: main salt, complexing agent, conductive salt, activator, cuprous ion complexing agent, pH stabilizer and brightening agent. The method comprises the following steps: adding complexing agent in water, stirring to dissolve complexing agent, obtaining a solution A; adding main salt in the solution A, stirring to dissolve main salt, obtaining a solution B; adding conductive salt in water, stirring to dissolve conductive salt, obtaininga solution C; mixing the solution B and solution C, adjusting the pH value to 2.0-4.5 with sulfuric acid or sodium hydroxide, obtaining a solution D; adding additive in the solution D, adding water to perform constant volume process and obtaining the alkaline non-cyanide plating solution for copper-plating in the desired volume for use, wherein the additive is activator, cuprous ion complexing agent, pH stabilizer and brightening agent.

Leveler Effect and Oscillatory Behavior during Copper Electroplating

Abstract: The electrochemical behavior of levelers was studied and compared for two commercial Cu plating chemistries in an effort tocorrelate the electrochemical behaviors with their impacts on bottom-up filling, impurity incorporation, and grain structures. Whilea strong complexing between leveler and accelerator resulted in a leveler-sensitive bottom-up filling rate and low impurity levelin the deposit, a traditional non-interacting leveler showed little impact on the filling performance and yielded a high impurityincorporation. An oscillatory behavior was reported for the strongly-interacting leveler chemistry during galvanostatic plating, thisoscillation manifested itself in both the potential and impurity incorporation. High impurity incorporation is known to inhibit the Cugrain growth; a laminated structure with alternating layers of big and fine Cu grains was obtained by annealing the Cu films platedwith the oscillatory behavior.© 2012 The Electrochemical Society. [DOI: 10.1149/2.020209jes] All rights reserved.Manuscript submitted May 18, 2012; revised manuscript received June 11, 2012. Published August 14, 2012. This was paper 2445presented at the Vienna, Austria, Meeting of the Society, October 4–9, 2009.

Filling through holes and blind microvias with copper using reverse pulse plating and insoluble anodes

Abstract: Purpose – The purpose of this paper is to present a summary of development work made in technical centres and on the subsequent customer qualification of copper filled through holes and blind microvias.Design/methodology/approach – Various copper deposition parameters were investigated in a small‐scale production line which was then extended to full‐scale production qualification in a horizontal conveyorised system. Samples of substrates with copper filled through holes were qualified at end‐user facilities.Findings – The copper plating process may be used to replace an existing production process for printed circuit boards. The proposed system can give a more reliable result in terms of filling and technical capability for the produced substrate. Overall production cost savings are possible.Research limitations/implications – The technology is based on a copper plating electrolyte using a redox pair for copper replenishment. The results achieved depend on use of this system and on production equipment wh...

Copper or copper alloy reduced in -ray emission, and bonding wire obtained from copper or copper alloy as raw material

Abstract: Copper or a copper alloy each characterized by having an α-ray emission of 0.001 cph/cm2 or less. As recent semiconductor devices have been made to have a higher density and a higher capacity, soft errors are more apt to occur therein because of the influence of α rays emitted from materials present in the vicinity of the semiconductor chips. In particular, the copper or copper alloys which are to be used in the vicinity of semiconductor devices, such as copper or copper-alloy wire leads, copper or copper-alloy bonding wires, and soldering materials, are strongly required to have a higher purity. There is also a need for a material reduced in α-ray emission. The present invention hence addresses the problems of elucidating the phenomenon in which copper or copper alloys emit α rays and of obtaining both copper or a copper alloy and a bonding wire formed from the copper or copper alloy as a raw material, the copper or copper alloy having been reduced in α-ray emission and being applicable to the desired material.

Electrolytic copper foil, method of producing electrolytic copper foil, lithium ion secondary cell using electrolytic copper foil as collector

Abstract: The present invention provides an electrodeposited copper foil having a tensile strength of at least 300 MPa and elongation rate of at least 3.0% after heat treatment at 350° C. for 1 hour and provides a copper foil which prevents the breakage of a current collector (copper foil) while maintaining adhesiveness between the current collector (copper foil) and the active material in response to substantial expansion and contraction of a Si or Sn alloy-based active material. The foil is an electrodeposited copper foil having a roughened surface, the tensile strength of the copper foil being at least 300 MPa after heating at 350° C. for 1 hour, the elongation rate being at least 3.0% after heating at 350° C. for 1 hour, and respective surface area ratios (actual surface area/geometric surface area) of both sides of the copper foil (the side that is roughened and the side that is not roughened) being from 1.6 to 2.2. The electrodeposited copper foil is produced with an electrolyte in which from 3 to 20 ppm of organic additives of one or more compounds selected from compounds having a structure with an SH group binding to a heterocycle containing N or thiourea-based compounds is added to a copper sulfate-based electrolyte, and then from 0 to 12 ppm of hydroxyethyl cellulose or a low-molecular weight glue, and from 10 to 80 ppm of chlorine ions are added thereto.

Electromagnetic interference shielding material from electroless copper plating on birch veneer

Abstract: Copper coating on birch veneer substrate was conducted by electroless deposition to prepare electromagnetic interference shielding material. In the process, Pd2+ ions were chemically adsorbed on the wood surface modified with chitosan. Then, they were reduced and dipped into a plating bath where copper film was successfully initiated. The coatings were characterized by SEM–EDS, XPS, and XRD. The metal deposition, surface resistivity, and electromagnetic shielding effectiveness were measured. The morphology of the coating observed by SEM is uniform, compact, and continuous. EDS, XPS, and XRD results showed that the coating consists of Cu0 with crystalline structure. Moreover, the copper films firmly adhere to the wood surface. Birch veneers plated with crystalline copper film exhibit high electro-conductivity with surface resistivity of 119.1 mΩ cm−2 and good electromagnetic shielding effectiveness of over 60 dB in frequencies ranging from 10 MHz to 1.5 GHz.

Textile design application via electroless copper plating

Abstract: Metallized textile has metallic color with reflective effect and smooth handle. The electroless copper plating on fabric using hypophosphite as a reducing agent is feasible process for design application. This study aims to investigate the appearance of the copper-plated Green-PN fabric produced by electroless plating with different deposition conditions including different nickel sulfate concentrations and pH of plating bath. Various colors were produced after the copper-plated fabrics had been exposed to the copper plating bath at 85°C and pH 8.5 for different time. Design application of the electroless copper plating on Green-PN fabric and Black-CVPN fabric was carried out. The electroless copper plating could change the original appearance of the fabric through the deposition of copper particles on the fabric surface. The final pattern was well-defined using many details such as lines and forms created by the design methods. The study laid the foundation of the electroless copper plating for textile d...

Conductive layer deposition and peel tests on biodegradable printed circuit boards

Abstract: Biodegradable plastics are novel materials which can be degraded by organic methods. The aim of the work was to investigate the usability of a cellulose-acetate (CA) and a polylactide (PLA) based material as a printed circuit board (PCB) with conductive layer peel tests. The common types of conductive layer coating processes were proposed: copper foil lamination, copper electroplating and thick film conductive layer deposition. The paper focuses solely of copper foil lamination. The laminates were examined by optical microscopy. The copper layer peel tests were mainly used to determine the bonding strength of the conductive layer, according to the instructions of IPC-TM-650 standard. Future investigations will involve application and test of the other conductive layer deposition processes, also the possible soldering methods, and thermal stability of the biodegradable PCBs.

Method for copper plating

Abstract: A method for copper plating in a plating bath wherein the substrate is brought into contact with a leveller additive comprising a heterocyclic core having a thiol group and an amino group attached to said heterocyclic core by a spacer is disclosed. Said method is particularly suitable for filling recessed structures in the manufacture of printed circuit boards, IC substrates and semiconducting substrates.

Influence of pH Solution on Electroless Copper Plating Using Sodium Hypophosphite as Reducing Agent

Abstract: The effect of pH solution on the electroless deposition of copper-rich Cu–Ni–P alloys, using hypophosphite as reducing agent, has been carried out. The deposition rate increased obviously with the increase of pH. The surfaces morphology, the roughness and the cristallinity depend many of pH. The kinetics of copper electroless was investigated by means of cyclic voltammetry and electrochemical impedance spectroscopy. The shape of voltammogramms and impedance diagram depend also of the pH solution.

Fabrication of Three-Dimensional Metalized Movable Microstructures by the Combination of Two-Photon Microfabrication and Electroless Plating

Abstract: We propose a method to fabricate three-dimensional (3D) metallic movable microparts by the combination of two-photon microfabrication and electroless plating. In this method, polymeric movable microparts with anchors made by two-photon microfabrication are metalized by electroless plating, and then the anchors are removed by laser ablation using a femtosecond pulsed laser. As a result, a metalized freely movable micropart whose motion is restricted to a shaft can be produced. We succeeded in fabricating sophisticated 3D metallic microrotors by adjusting the experimental conditions of both electroless copper plating and laser ablation.

Electroless copper plating solution

Abstract: The invention belongs to the field of electroless copper plating, in particular to electroless copper plating solution The electroless copper plating solution comprises the following components in concentration: 5 to 20 grams per liter of copper salt, 5 to 15 milliliters per liter of formaldehyde, 25 to 65 grams per liter of complexing agent, 8 to 20 grams per liter of pH regulator, 5 to 20 grams per liter of pH buffer, 005 to 1 gram per liter of polyethylene glycol, 10 to 60 milligrams of 2-2 cross-linked pyridinoline, 1 to 20 milligrams per liter of 2-mercapto benzimidazole, 005 to 1 gram per liter of ferrite and 5 to 50 milliliters per liter of methanol The electroless copper plating solution provided by the invention is used in an electroless copper plating process for directly metalizing a circuit board, and the formed plating has a bright appearance color and a low impurity content The thickness of the plating is improved greatly to over 20 micrometers The electroless copper plating solution can accelerate plating speed to over 10 micrometers per hour