Electronic packaging, thermal performance

TLCPs have many outstanding properties that uniquely qualify them for these high performance multilayer boards (12). Table 7 compares the applicability of LCPs with other state-of-the-art materials for electronic packaging. They can be made into very thin, self-supporting films (<50 J.m) with a controllable CTE. By processing LCP films as described above, circuit substrates can be manufactured with a CTE around 7 ppm/°C and thermal stability over 250°C. TLCPs do not require secondary resins for fabrication into MLBs, they can be thermally bonded to themselves and to copper foil. Control of molecular orientation has been shown to result in a substrate with the desired CTE of 6 to 7 ppm/°C for matching alumina, or 16 ppm/°C for matching copper. 

The thermal characteristics of NR-metal composites are close to the properties of metals, whereas the mechanical properties and the processing methods are typical of polymers.Thermally conducting, but electrically insulating, polymer-matrix composites are increasingly important for electronic packaging because the heat dissipation ability limits the reliability, performance and miniaturization of electronics.Thermal properties such as thermal conductivity, thermal dilfusivity and specific heat of metal (copper, zinc, Fe and bronze) powder-filled polymer composites are investigated experimentally in the range of filler content 0-24% by volume. ... 

The development of modern technologies demands electronic devices with superior performance reflected in multiplication of their functionality (Tong 2011). One of the challenges in electronic packaging is to overcome barriers concerning thermal management, which is a common problem that can reduce... 

The aim of the practical assignments for Quantenchemie is to enable the students to perform their own ab initio quantum chemical studies using off the shelf application software packages. There is also the goal to prepare the students to critically read the scientific literature in this area of research. Under this mission, we designed a set of problems which illustrates the capabilities of the different methods and the systematic errors involved (basis set truncation, electron correlation, thermal corrections, etc.) on a broad (but not systematic) range of chemical problems. Towards the end of the course only, the level of theory applied exceeds the levels of second order perturbation (MP2) or density functional theory. This also reflects the time limits imposed on the class (90 minutes per unit 7 units total no homework assignments). 

The last and most advanced system presented in this book includes an array of three MOS-transistor-heated microhotplates (Sect. 6.3). The system relies almost exclusively on digital electronics, which entailed a significant reduction of the overall power consumption. The integrated C interface reduces the number of required wire bond connections to only ten, which allows to realize a low-prize and reliable packaging solution. The temperature controllers that were operated in the pulse-density mode showed a temperature resolution of 1 °C. An excellent thermal decoupling of each of the microhotplates from the rest of the array was demonstrated, and individual temperature modulation on the microhotplates was performed. The three microhotplates were coated with three different metal-oxide materials and characterized upon exposure to various concentrations of CO and CH4. 

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