Identification of fibre composition of apparel for recycling

We present the results of a recent review of fibre identification technologies for apparel recycling. The review focuses on tagging and labelling approaches that can help apparel recyclers identify the material composition of the recycling grades of apparel, in preparation for the introduction of more material-specific recycling technologies. We conclude that the adoption of the 2D barcode linked to an external database will both contain sufficient bits to encode useful information, and that such an approach could also give consumer (and hence brand) benefits that would help make the business case for their introduction

Suitable thicknesses of base metal and interlayer, and evolution of phases for Ag/Sn/Ag transient liquid-phase joints used for power die attachment

Both real Si insulated gate bipolar transistors (IGBT) with conventional Ni\Ag metallization and a dummy Si die with thickened Ni\Ag metallization have been bonded on Ag foils electroplated with 2.7 m and 6.8 m thick Sn as an interlayer at 250ºC for 0 min, 40 min and 640 min. From microstructure characterization of the resulting joints, suitable thicknesses are suggested for the Ag base metal and the Sn interlayer for Ag/Sn/Ag transient liquid phase (TLP) joints used in power die attachment, and the diffusivities of Ag and Sn in the Ag phase are extracted. In combination with the kinetic constants of Ag3Sn growth and diffusivities of Ag and Sn in Ag reported in the literature, the extracted diffusivities of Ag and Sn in Ag phase are also used to simulate and predict the diffusion-controlled growth and evolution of phases in the Ag/Sn/Ag TLP joints during an extended bonding process and in service

LHC1: a semiconductor pixel detector readout chip with internal, tunable delay providing a binary pattern of selected events

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

A review of flip-chip GaAs circuits, models, interconnections and modelling techniques in use at Marconi

Broadband high frequency systems are increasingly utilising MMIC technology to reduce circuit design uncertainties. At frequencies above 6 GHz the MMIC interconnections become critical, bond wire inductances become significant and bond length variations in the assembly process cause significant performance variation. At Marconi Electronic Systems the benefits of solder bump connections to the MMIC are being explored. These benefits include very low inductance, self-alignment and repeatable connections. The technology is also extremely well suited to automatic and semi-automatic production, making multiple channel systems such as phased arrays more cost-effective. This paper is a review of recent work (2-40 GHz) on solder bumped MMIC circuits and covers broadband flip-chip S-parameter circuit interconnect modelling, thermal modelling of HEMT transistors connected by solder bump arrays. Additional layers to the MMT H40 Foundry process have been specially designed to facilitate solder bump connection