Gold coatings play an important role in flux-free joining in a vacuum -a method widely used in electronics fabrication. In this process, the gold coating provides a substitute for the flux, ensuring that the surfaces of the joint are oxide free and solderable.

Principles of Soldering serves as a problem-solving guide for engineers who work with soldering processes and soldered components and assemblies. It begins with a review of key process parameters, including surface energy and tension, wetting and contact angle, fluid flow, filler spreading characteristics, dissolution of parent materials, and intermetallic growth. It then examines the factors that influence the functional integrity of soldered joints and the practicality of the process employed. It discusses the metallurgy of solder alloy systems, the effect of metallic impurities, and the use of phase diagrams to better understand and control the soldering process. It explains how joining atmospheres influence chemical reactions and how fluxes help remove surface oxides and other films. It describes the benefits of fluxless soldering and the role of materials in defining process constraints. It also covers lead-free solders, bump bonding, amalgams, and diffusion soldering as well as mechanical property testing, joint characterization and modeling techniques, and solderability standards. For information on the print version, ISBN 978-0-87170-792-5, follow this link.

Principles of Brazing serves as a problem-solving guide for anyone who works with brazing processes or designs component joints. It covers key brazing parameters such as surface energy and tension, wetting and contact angle, and filler spreading characteristics; design considerations including mechanical integrity and electrical and thermal conductivity; and practical concerns such as workholding, cleaning procedures, and process control. It discusses the metallurgy of brazing alloy systems; the effect of impurities, joining atmospheres, and chemical fluxes; and the role of materials in defining process constraints. It also provides information on diffusion brazing, direct brazing processes for nonmetals, and brazes for jewelry. For information on the print version, ISBN 978-0-87170-812-0, follow this link.

The Omega3/LHCl pixel detector readout chip comprises a matrix of 128 X 16 readout cells of 50 mu m X 500 mu m and peripheral functions with 4 distinct modes of initialization and operation, together more than 800 000 transistors. Each cell contains a complete chain of amplifier, discriminator with adjustable threshold and fast-OR output, a globally adjustable delay with local fine-tuning, coincidence logic and memory. Every cell can be individually addressed for electrical test and masking, First results have been obtained from electrical tests of a chip without detector as well as from source measurements, The electronic noise without detector is similar to 100 e(-) rms. The lowest threshold setting is close to 2000 e(-) and non-uniformity has been measured to be better than 450 e(-) rms at 5000 e(-) threshold. A timewalk of < 10 ns and a precision of < 6 ns rms on a delay of 2 mu s have been measured. The results may be improved by further optimization

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