Ni-B Deposits Research Articles

Direct Patterning of NiB on Glass Substrates Using Microcontact Printing and Electroless Deposition

We investigate a method to direct the electroless deposition (ELD) of NiB on glass by microcontact-printing a reagent from an elastomeric stamp onto a glass substrate. There are three variants of this method depending on the reagent to be printed. ELD of a metal on a glass substrate necessitates the pretreatment of the glass with organic linkers that can bind a catalyst from solution. We use colloidal Pd/Sn as catalyst and immobilize these particles via an amino-functionalized silane such as 3-(2-aminoethylamino)-propyltrimethoxysilane (EDA-Si) grafted to the glass substrate. The first variant includes microcontact-printing EDA-Si onto glass to bind the colloidal Pd/Sn catalyst at well-defined locations on the substrate. Here, the stamp is first hydrophilized with an O2-based plasma and then inked using different methods that include wet-inking, inking of the silane through the vapor phase, and contact inking. ELD of NiB initiates in those regions of the substrate that were previously microcontact-printed. This approach entails the problem of inking and printing of an excess of silane, which can be washed away from the printed regions and can thereby induce the ELD of NiB grains adjacent to the desired pattern. In the second approach, the entire glass is uniformly derivatized with EDA-Si, and colloidal Pd/Sn particles are inked onto a stamp and microcontact-printed to activate the substrate where desired. These colloids do not diffuse on the substrate during printing and subsequent steps, allowing the formation of NiB patterns having excellent contrast and accuracy even over areas as large as 4‘ ‘ in diameter. Similar to the first method, inking and reusing stamps is inconvenient because the colloids are suspended in a solution of concentrated HCl and the stamp needs to be hydrophilized and covered with a thin layer of a polyelectrolyte to achieve homogeneous inking of the stamp with these colloids. The third and most promising approach is to derivatize the glass substrate homogeneously with both EDA-Si and Pd/Sn colloids and then deactivate the catalyst selectively prior to the ELD step by microcontact-printing eicosanethiol (ECT). In this case, it is possible to employ hydrophobic PDMS stamps, to reuse them, to optimize the inking and printing conditions, and to form high-quality NiB structures with lateral dimensions ranging from several hundred to below 1 μm. This work suggests that microcontact printing (μCP) and ELD can be combined in a variety of manners to provide interesting alternatives to conventional microfabrication methods that otherwise include the deposition of metals in a vacuum process and patterning methods based on photolithography.

Electroless Deposition of NiB on 15 Inch Glass Substrates for the Fabrication of Transistor Gates for Liquid Crystal Displays

The thin-film transistor (TFT) array of liquid-crystal displays (LCDs) comprises a number of metallic, semiconducting, and insulating layers, which need to be deposited and patterned accurately with very high yields on a (large) glass substrate. We are exploring how to fabricate the gate metal lines of the TFT array in an entirely new and potentially cost-effective wayby depositing the metal layer of the TFT array using electroless deposition (ELD) and by patterning the gates using microcontact printing (μCP). To achieve this goal, we separately explore first the plating conditions to deposit a gate metal on 15 in. glass substrates, and second the printing process to finally combine them later in the work. Here, we review in depth the metallization of the glass by ELD of NiB as gate material, and we demonstrate the patterning of the gate layer using a conventional photoengraving process (PEP, i.e., photolithography and wet etching). We selected NiB because this material can fulfill the conductivity requir...

Self-Assembled Monolayers of Eicosanethiol on Palladium and Their Use in Microcontact Printing

We investigate self-assembled monolayers on polycrystalline Pd composed of eicosanethiol (ECT). X-ray photoelectron spectroscopy reveals a composition and structure of the ECT monolayer on Pd similar to those on Au: the sulfurs are close to the Pd and underneath the alkyl chains. Monolayers formed from a 0.4 mM solution of ECT in ethanol are 2.8 nm thick and have advancing and receding contact angles with water of ∼115° and ∼90°, respectively. They are 0.3 nm thicker than those on Au and have a surprisingly low receding contact angle. Monolayers of ECT microcontact printed onto 100-nm-thick evaporated Pd films confer good protection of the Pd in a ferrichloride wet etch. It is therefore possible to create Pd patterns with high contrast and with lateral dimensions smaller than 200 nm. The Pd patterns can initiate electroless deposition of NiB, NiP, or Cu but are difficult to use as a mask for etching a less noble metal such as Cu due to the formation of a galvanic cell during etching. Instead, this galvan...

Properties of electroless Ni-W-P amorphous alloys

This paper describes work performed to determine some of the properties of the electroless Ni-W-P amorphous deposits. Phosphorus contents were varied up to 32 at.%, and the amorphous structure was found to be present at phosphorus contents above 5 at.%. Irrespective of P content, all the deposits exhibited excellent adhesion to metallic substrates. The addition of even small amounts of W provided greatly increased hardness compared with the plain Ni-P deposits. The wettability properties of the Ni-W-P deposits were found to be comparable to those of Ni-P and N-B-P deposits but inferior to those of Ni-B deposits.

Wear resistance of metastable Ni-B alloys produced by chemical vapor deposition

A manufacturing application of the chemical vapor deposition of nickel from Ni(CO) 4 is the near-net-shape production of high-quality mold or die forms. In certain high wear applications, e.g. transfer molding of a glass-filled epoxy, erosive wear of the nickel die can compromise dimensional control of the product. We have investigated the atmospheric pressure deposition (at 150–155°C) of Ni-B from Ni( CO) 4 + B 2 H 6 gas mixtures in order to develop alloys with improved hardness and wear resistance. The as-deposited alloys are metastable solid solutions of boron in nickel and contain up to 37 at.% B. Evaluations of the alloys in the as-deposited and annealed states have included micro-indentation hardness and 1000-cycle pin- on-disc wear and friction studies using glass-filled epoxy pins. Two high boron alloys are shown to provide excellent resistance to wear when sliding against the glass-filled epoxy.

Studies on the Electroless Nickel Plating with NaBH4 as a Reducing Agent XI. Application of Computer Analysis for the Evaluation of Corrosion Resistance of Electroless Ni-B Deposits

Studies on the Electroless Nickel Plating with NaBH4 as a Reducing Agent XI. Application of Computer Analysis for the Evaluation of Corrosion Resistance of Electroless Ni-B Deposits

An ESCA Study of the Electroless Ni-B Deposits

An ESCA Study of the Electroless Ni-B Deposits

Composite nickel-boron electrolytic coatings

1. The feasibility has been demonstrated of producing composite Ni-B electrodeposits with a uniform distribution of boron particles throughout their matrix. 2. Diffusional annealing leads to the formation of qualitatively new structures in such deposits and improves their physicomechanical characteristics. 3. The wear resistance of heat-treated Ni-B deposits is as high as, and frequently much higher than, that of hard chromium electrodeposits.

無電解ニッケル-ホウ素メッキ皮膜の熱処理による相変化

The phase changes in electroless Ni-B deposits during heat treatment are reported in this paper.The experiments were conducted by thermal and X-ray analyses in nearly the same method as in the previous reports.The results obtained were as follows:1) The hardness after heat treatment of electroless Ni-B deposits exhibited its maximum at about 400°C as shown in the curves.2) Exothermic change was observed at about 270°C in the curves plotted by thermal analysis of electroless Ni-B deposits.3) It was possible to comfirm the formation of nickel boride at the temperature of exothermic change, judging from the X-ray diffraction pattern of electroless Ni-B deposits.