Particulate bis[1-(hydroxy-O)-2(1H)-pyridinethionato-S-2]-(T-4)-zinc (zinc pyrithione; ZPT) in the diameter range 0.5-0.7 mu m is a US FDA-approved anti-dandruff active widely used in anti-dandruff shampoos. A nanoparticulate form of ZPT is expected to exhibit a higher activity, be distributed more effectively on the scalp, require less thickening agent in the shampoo formulation to ensure its stability against settling than the standard form of ZPT, and would enable clear anti-dandruff shampoo formulations. We demonstrate, for the first time, that a green, mechanochemical nanoparticle synthesis process can be used to prepare nanoparticulate ZPT from zinc chloride and sodium pyrithione monohydrate. Both a Reeves attrition mill and a Retsch MixerMill were found to be effective tools for delivering the mechanical energy needed for the conversion. The infrared spectra and X-ray powder diffraction patterns for the products correspond to those for the known desired material. Transmission electron microscopic analysis indicates that ZPT nanoparticles with primary particle diameters in the range of 20-200 nm (mean diameters of 65-100 nm) can be obtained via this method.

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Commercial electronic devices require shielding solutions that ensure electromagnetic compatibility (EMC) while accounting for effects of specific enclosure structural features such as seams, vents, and port dimensions. In practice, suitable EMC materials combine with the device operating characteristics to determine an overall shielding response. To optimally couple plastic design practices with EMC requirements, both polymer materials science and electrical engineering concepts, must be considered. Use of extrinsically conductive polymer (ECP) formulations for electronic applications has advantages in that they can be directly molded to a desired shape and serve to provide the necessary shielding while also meeting mechanical integrity requirements. Shielding and mechanical performance can be varied via filler loading or altered through wall thickness changes to satisfy demands associated with a particular device. Injection-moldable ECP polycarbonate-based formulations can attain average shielding effectiveness (SE) levels of similar to 50-60 dB through 2 GHz at 2-mm thickness as measured using ASTM D 4935 procedures. These values vary with thickness, and SE improvements of similar to 10-20 dB are observed when increasing from I to 2 mm. Additionally, resultant mechanical properties of shielding composites are strong functions of overall fiber content. These interrelated material and shielding characteristics, which form the basis for filled conductive polymer use within practical enclosure shielding designs, are described. (c) 2007 Wiley Periodicals, Inc.

In this paper, we report on the integration of a spin-on low-k material (ENSEMBLE(TM) PMD) at the pre-metal dielectric (PMD) level of CMOS logic circuits processed using 0.13@mm node modules. Modifications to the conventional integration flow, where high-density plasma phospho-silicate glass (HDP-PSG) is used as PMD material, are made to the planarization steps and etch/strip sequence. Although on stand-alone transistors there is no measurable impact of the lower capacitance, a significant decrease of the switching delay of invertors in ring oscillator structures loaded with a metal/poly plate capacitor is observed. This demonstrates the possible positive impact of low-k on the performance of circuits of which the lowest level of back-end routing has a large overlap to underlying silicided areas.

La presente invention concerne un procede qui consiste a prendre un substrat, a former une premiere couche sur ce substrat, cette premiere couche possedant une constante dielectrique inferieure a 3,0 et comprenant un polymere organique, a appliquer une resine organosilicate sur cette premiere couche, a retirer une partie de cette resine organosilicate de facon a exposer une partie de la premiere couche, et a retirer les parties exposees de cette premiere couche. Cette invention concerne aussi un circuit integre comprenant un substrat actif contenant des transistors et une structure d'interconnexion electrique contenant un schema de traces metalliques separes, au moins partiellement, par des couches ou des regions d'un materiau polymere organique possedant une constante dielectrique inferieure a 3,0 et comprenant aussi une couche d'une resine organosilicate au dessus d'au moins une couche de ce materiau polymere organique.

Adherence to the prescript of Moore’s law continues to drive materials development for new and lower dielectric constant materials for use as back-end-of-line (BEOL) interlayer dielectric in advanced logic IC’s. As is the case for the current generation of low-K materials (<3.0), these ultra-low K materials (<2.2) will need to meet the variety of integration and reliability requirements for successful product development. Excluding the incorporation of fluorine to lower the material polarity, further reductions of dielectric constant can only be achieved by reduced density. Based upon the industry’s experience with the current class of full density dielectrics, process integration may be challenging for ultra-low K materials. This anticipated difficulty derives from the profound differences in material properties, e.g. mechanical integrity, as one lowers the material density, which in turn confounds existing manufacturing processes that have evolved over 35 years based on silicon dioxide. Minimizing these material and processing differences by extending leveraged learning from previous technology nodes is essential for timely and cost-efficient development cycles. As a result, material selection of a full density low-K is somewhat influenced by the ability of that material to be extended into future generations. Understanding how the material properties will change as its density is lowered is vital to this selection process. In this paper, we present a summary of models for calculating effective properties as a function of density and apply these to current low-K materials with emphasis on mechanical integrity. We will also review experimental methods for measuring the mechanical integrity of ultra-low K materials and compare the results to the various models described herein.

The performance of a new thermally conductive mold compound containing SCANTM Silica Coated Aluminum Nitride filler has been investigated for use with power MOSFET devices in the SO-8 package. Thermal performance was determined through measurement of junction-to-ambient thermal resistance (Rθja), both in still air and in a wind tunnel environment. Additionally, the devices were evaluated for shifts in electrical characteristics and extensive reliability testing was performed. It was found that the SCAN filler material reduced the Rθja by 8 to 13% (compared to the standard angular silica filler material) while causing no shifts in electrical characteristics and no degradation in device reliability. It was concluded that the while our version of the SO-8 package (with fused leadframe) would not realize the maximum potential benefit from a thermally enhanced mold compound, the mold compound containing SCAN filler would provide a measurable increase in thermal performance which allows for an increased current rating of the device and lower typical junction temperatures

Thermal demands on electronic packages are increasing. Resolving these issues in plastic packaging frequently involves a balance of engineering, performance and cost. Conventional plastic packages exhibit limited thermal performance. Thus, engineering solutions, such as modified lead frames, heat sinks or spreaders, which often involve a significant increase in cost, must be considered in those applications where heat dissipation requirements exceed design capabilities. The use of a novel hydrolytically-stable aluminum nitride filler (SCAN), replacing standard fused silica fillers, in transfer molded plastic packages offers another option. AlN is an inorganic dielectric possessing a thermal conductivity much higher than standard silica fillers. Molding compounds and various device packages based on this powder have been introduced commercially. These packages offer large improvements in thermal performance, comparable to heat spreaders and in some cases, exposed heat slugs: reductions of 25-30% in /spl Theta//sub ja/ and 50% in /spl Theta//sub jc/, respectively are typical. Reliability data, including electrical, thermal, environmental and mechanical properties, measured for QFP and SOIC packages indicate that SCAN-based packages exhibit reliability equivalent to packages molded with standard molding compounds. Perhaps most importantly, these packages may also offer significant cost savings, depending on the specific package type.

A new filler material, SCAN, silica-coated aluminum nitride, has been developed by The Dow Chemical Company for microelectronic plastic packaging. SCAN is a hydrolytically stable aluminum nitride material with appropriate particle size distribution and thermal conductivity to be used as a filler material for molding compounds or glob-tops where power dissipation is required. The patented silica coating process imparts hydrolytic stability to the powder and modifies the surface chemistry to make it more compatible with resin formulations that have traditionally used fused silica