Seedless electroplating on patterned silicon

Nickel thin films have been electrodeposited without the use of an additional\ud seed layer, on highly doped silicon wafers. These substrates conduct\ud sufficiently well to allow deposition using a peripherical electrical contact on\ud the wafer. Films 2 μm thick have been deposited using a nickel sulfamate\ud bath on both n+- and p+-type silicon wafers, where a series of trenches with\ud different widths had been previously etched by plasma etching. A new,\ud reliable and simple procedure based on the removal of the native oxide layer\ud is presented which allows uniform plating of patterned substrates

Performance of inkjet-printed structures on different substrate materials under high humidity and elevated temperature conditions

Inkjet printing is widely being researched as enabling technology for printed electronics; however, there are scarce publications concerning the reliability of inkjet-printed structures on different substrates. The reliability of such structures under high humidity and high temperature conditions is treated in this work. To do so, the adhesion and resistivity of printed structures on PET, Rogers, PI and FR-4 materials are studied before and after a moisture resistance test. The samples present average resistivity values in the range of 12-106 μΩ·cm and only one specimen of the Rogers sample fails the reliability test. The Rogers sample presents perfect adhesion characteristics, the adhesion can be improved for the rest of the samples, especially for the PI sample. The general performance of inkjet-printed structures on different substrate materials is good

Reliable inkjet-printed interconnections on foil-type li-ion batteries

Shapeable rechargeable Li-ion batteries are a good option for the power source of system-in-package devices; nevertheless, their size and temperature limitations are a constraint during the fabrication process. Inkjet-printed interconnections on top of the battery are proposed in order to reduce the size and costs of wireless sensor network devices that require the use of Li-ion batteries. The reliability of such interconnections under high-humidity and elevated-temperature conditions is characterized in terms of electrical and adhesion properties; the micro- and macrostructures of the ink are observed in detail. Two silver inks are used to print the interconnections. The resistivity values of printed structures are in the range of 8.6-47.6 μΩ·cm, and all of them pass the reliability tests. The adhesion characteristics are good for Ink A; however, Ink B presents failures under high-humidity conditions. For a good adhesion, a plasma treatment should be performed prior to printing. The electrical performance of the interconnections is not affected by high-humidity and high-temperature conditions. Furthermore, there is no indication of silver migration. It is recommended that the curing temperature of the ink is kept low (<; 155°C) in order to avoid cracks in the ink structure and damages to the battery's packaging foil. The interconnections should be printed before filling the battery to avoid the decomposition of the electrolyte which happens at 80 °C

Mechanical properties of Indonesian-made narrow dynamic compression plate

Osteosynthesis plates are clinically used to fixate and position a fractured bone. They should have the ability to withstand cyclic loads produced by muscle contractions and total body weight. The very high demand for osteosynthesis plates in developing countries in general and in Indonesia in particular necessitates the utilisation of local products. In this paper, we investigated the mechanical properties, i.e. proportional limit and fatigue strength of Indonesian-made Narrow Dynamic Compression Plates (Narrow DCP) as one of the most frequently used osteosynthesis plates, in comparison to the European AO standard plate, and its relationship to geometry, micro structural features and surface defects of the plates. All Indonesian-made plates appeared to be weaker than the standard Narrow DCP because they consistently failed at lower stresses. Surface defects did not play a major role in this, although the polishing of the Indonesian Narrow DCP was found to be poor. The standard plate showed indications of cold deformation from the production process in contrast to the Indonesian plates, which might be the first reason for the differences in strength. This is confirmed by hardness measurements. A second reason could be the use of an inferior version of stainless steel. The Indonesian plates showed lower mechanical behaviour compared to the AO-plates. These findings could initiate the development of improved Indonesian manufactured DCP-plates with properties comparable to commonly used plates, such as the standard European AO-plates