Electroless nickel plating applications

After the sintering stage, electrodes are applied, usually either by electroless nickel plating or by painting or screening on specially adapted silver paint. Leads are then soldered to the electrodes when, for many applications, the device is complete in other cases it may be encapsulated in epoxy or silicone resins. Examples are illustrated in Fig. 4.15. 

Applications Hypophosphites are mainly used in electroless nickel plating (e.g. deposition of nickel phosphorus layers with 8 to 10% P in the Kanigan process). 

Selective electroless nickel plating of particle arrays on polyelectrolyte multilayer was investigated for the potential applications in sensors, optoelectronics, and biochips.96 This process is based on the preparation of functional colloidal arrays on surfaces. In the next step metal deposition is carried out on the surfaces of the patterned particles secured on the substrate. Samples of colloidal arrays on patterned polyelectrolyte templates are first pretreated with a Pd(II)-based catalyst. After rinsing with deionized water and drying, samples were plated with nickel using dimethylamine borane (DMAB) as a reducing agent. Based on the results of this work,96 it was shown that the selective electroless nickel deposition on 3D patterned surfaces can be successful. 

Organic acids are usually separated by means of ion-exclusion chromatography and detected via their electrical conductivity. Applications are mainly in the field of copper and electroless nickel plating baths. 

H. Kikuchi, S. Oka and C. Nakatsuka, Continuous regeneration method of electroless nickel plating bath, Jpn. Pat. JP 63-41983 (examined application) S. Izumi, S. Fujita, Y. Taniguchi and H. Kikuchi, Reliability of print circuit prepared by copper electroless plating, Denshi Zairyou (Electric Parts Mater.), 1986, 25, 27. 

Copper/beryllium alloys (thermal conductivity 200 W/mK) and copper/cobalt/ beryllium alloys (225 W/mK) for nozzle casings and tips in applications up to aromid 280 C (see Figure 4.5a) (because of the mechanical strength of the alloy, which rapidly falls when the temperature rises). Treatment involving an overlayer of silicon carbide increases injection abrasion resistance with, for example, PA and GF. Nickel coating eliminates the influence of copper on the melt (electroless nickel plating) ... 

Fig. 8.20 Applications of electroless nickel plating Ni-P deposits for wcar>resistant and corrosion-resistant applications in engineering, (a) A cooling-cail assembly. (Photo graphy courtesy Ionic Surface Treatments plating by Dudley Division.) (b) Printed circuit boards for a wrist watch and calculators. Electrically isolated areas of deposited copper may be built up by electroless nickel plating which also provides a corrosion-resistant and solderablc finish. The deposits are various NIKLAD electroless nickels. (Photograph Courtesy Lea Manufacturing.)...

Electroless nickel baths are usually preferred to electroless copper, since they tend to be more stable and are less likely to deposit metal on unwanted areas, such as plating racks. Electrolytic copper is then plated before the final application of nickel and chromium, where this is the required finish, as it... 

Carbon fibers electroplated with electroless nickel or other metals have also been developed for EMI applications. The plating increases the conductivity of the fibers about 30 times and adds magnetic properties. These metallized carbon fibers are generally in the size range of 2-8 p,m. (See also carbon fiber.)... 

There are more process steps involved in laser subtractive structuring (LSS) than in the additive or semiadditive processes (Fig. 3.2). Injection molding is followed by short surface activation to permit electroless copper or nickel plating. This chemical premetallization is followed by a galvanic process to build up the plating to target thickness. The next step is structuring as such, by application of an activatable etch resist. 

---