Flying machines, swimming machines, racing machines.
Watson Research Center P. BoxYorktown Heights, NYUSA February, Electroless deposition is the process of depositing a coating with the aid of a chemical reducing agent in solution, and without the application of external electrical power.
It is therefore applicable to non-conducting substrates, and has been used extensively for metallizing printed wiring boards Case involving motivation problem electro logic. Though electroless metal deposition rates are typically lower than those of electrolytic deposition rates, as dimensions of circuit lines continue to get smaller, electroless deposition will continue to be attractive for next generation PWB products which have much finer and thinner lines than traditional PWB products.
More recently, selective electroless deposition has been found to yield encouraging results in the case of the self-aligned cobalt-tungsten-phosphorus alloy capping, or barrier, layer on back-end-of-line BEOL copper interconnects, for example, in tests aimed at high performance logic chips at the CMOS 45 nm node and below.
Due to its confusion with other chemical deposition processes which also do not require external power, such as self-limiting chemical displacement for example, immersion tin coating of copper with a thin layer of tinelectroless deposition is understood here as being an autocatalytic, self-sustaining process, in which reducing electrons are obtained from a separate electroless solution-derived compound, called the reducing agent.
In this overview, attention will be primarily focused on electroless deposition of metallic films, and will focus on the fundamentals and challenges of a few example processes, rather than being a comprehensive discussion of recipes and applications.
Various other metals, including copper, and gold, were deposited from relatively short-lived solutions that contained reducing agents to create films, mainly on glass. Formaldehyde, which is still the foremost reductant used for electroless copper deposition despite safety concerns, featured prominently in the pre formulations.
A demarcation between pre-Brenner and Riddell and modern electroless deposition methods seems to exist in reviews of electroless deposition, in that negligible mention is given to the former period. There is some justification for this.
For example, early solutions were susceptible to homogeneous decomposition either slow or rapid plating out, precipitation of the metalsince metal ion complexants and solution stabilizers were not properly employed. In the case of the earlier electroless deposition-like processes, not only were modern electrochemical characterization methods not yet available the potentiostat was unavailablebut also absent was the notion of applying electrochemical concepts to develop an understanding of electroless deposition mechanisms.
Nevertheless, at least some of the currently used electroless solution formulations owe their beginnings to work carried out in the pres period. The increasing use of electroless deposition to metallize smooth, nonmetallic surfaces in microelectronics means that the achievement of deposit adhesion to smooth surfaces is as much an issue today as it was a century or more ago when chemical deposition processes were being developed for metallization of glass surfaces.
Electroless deposition as we know it today has had many applications, for example, in corrosion prevention and electronics.
Although it yields a limited number of metal and alloy deposits compared to of electrodepositionmaterials with unique properties, such as nickel-phosphorus corrosion resistance and cobalt-phosphorus magnetic properties based alloys, are readily obtained by electroless deposition.
In principle, it is easier to obtain coatings of uniform thickness and composition using the electroless process, since one does not have the current density uniformity problem of electrodeposition. However, as we shall see, the practitioner of electroless deposition needs to be aware of the actions of solution additives and dissolved oxygen gas on deposition kineticswhich affect deposit thickness and composition uniformity.
Nevertheless, electroless deposition is experiencing increased interest in microelectronics, in part due to its selectivity of deposition. Basic process An electroless solution typically consists of: A highly-dispersed catalyst, usually palladium, is often deposited on the surface to be plated on to initiate plating; palladium is a good catalyst for oxidation of most electroless reducing agents.
The basic electroless deposition process may be outlined as follows. Electrons derived from heterogeneous oxidation of a reducing agent at a catalytically active region of the surface reduce metal ions to metal atomswhich deposit on the surface, and a continuous metal deposit will be obtained under the right conditions.
See also the Appendix. Trace additives like lead may also undergo deposition as described, and, as mentioned, dissolved oxygen gas may also undergo a parasitic reduction reaction at the plating surface. The initial catalytically active region is normally a metal catalyst, often highly dispersed palladium that is active for oxidation of most common electroless reducing agents.
However, undesired deposition may also occur at catalytically active sites on container walls scratches, adsorbed metal particlesand at small particles in solution, which may exhibit some catalytic activity for reductant oxidation due to the relatively high energy of their surfaces and the presence of active sites.
With regard to the above described process where electrons reduce metal ions to metal atoms, which represents the metal deposition half reaction in electroless deposition, in a simplistic sense we see that it is analogous to an electrodeposition process. With respect to the reducing agent reaction, organic and relatively complex inorganic oxidation reactions have similarly been widely studied electrochemically.DEVELOPING MANAGEMENT SKILLS NINTH EDITION GLOBAL EDITION David A.
Whetten Kim S. Cameron Diagnostic Surveys for Creative Problem Solving Problem Solving, Creativity, and Innovation Gase Involving Motivation Problems Electro Logic SKILL PRACTICE Electro Logic is a small R & D firm in a mid western college town adjacent to a major university Main aim of this case study is to find out the reasons for employee low motivation, low ability, satisfaction and performance Abraham Maslow's Hierarchy of needs.
In Electro Logic the fact that major funding comes primarily from the government, the budget for this company was not fixed for a long term, employee benefits, Health insurance premiums can change any time, no job security for employees; thus employees levels of motivation, and consequently performance and Outcomes are negatively .
Case Involving Motivation Problems Electro Logic THE PUZZLE OF MOTIVATION HOOK: Before I start I would like to ask you how many of you have scientific methods this semester So you have to write a report and the subjects are fairly complex yet it is compulsory.
Most of you are probably thinking that you have to get started with this report soon but you can’t find any motivation .
The purpose of the present paper is to present case reports of patients with poor laryngeal elevation treated with computerized biofeedback therapy using dynamic acceleration measurements. Electro Logic is a small R & D firm in a mid western college town adjacent to a major university Main aim of this case study is to find out the reasons for employee low motivation, low ability, satisfaction and performance.