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High demands are placed on base materials for present‐day printed circuits. The requirements for multilayer materials are examined including satisfying criteria regarding low dielectric constant, high glass transition temperature and dimensional stability. Comparisons are made involving different resin systems and reinforcement materials. Improvements in material characteristics are often accompanied by disadvantages in terms of processability, copper peel strength and price. The properties of a number of paper‐based laminates and their requirements are discussed. It is concluded that no ‘ideal’ base material is available which simultaneously fulfills all demands including price.

Continuously increasing requirements drive multilayer manufacturers to search for advanced manufacturing technologies and to evaluate new materials. This paper provides an insight into new multilayer bonding methods, improvements offered by laminators, and why to select high performance materials for special applications.

The Dow Chemical Company has developed a new epoxy‐based system to serve the growing need for high‐performance dielectric substrates, requiring high thermal reliability (high T_g, high thermal resistance) and high signal speed and integrity (low dielectric constant and low loss factor). The system is based on advanced, proprietary resin technologies. The process latitude of this system is very similar to traditional high T_g FR‐4 products. The optimized rheology of the system leads to consistent, controlled flow. The copper foil JTCHTEAB from Gould Electronics, where AB stands for advanced bond, is interesting in this context as it was developed for use on high‐performance laminates with a typically lower ability for copper bonding, such as high T_g and low D_k/D_f substrates. When the “LDk‐HTd” resin is used in combination with the JTCHTEAB copper foil, the copper peel strength fully meets the industry standard for high T_g FR‐4 laminates.

The purpose of this paper is to investigate and present the properties of a new substrate material based on thermoplastic polymers (so‐called LuVo Board) for high‐frequency applications.

The thermal, mechanical and electrical properties of a new thermoplastic substrate are investigated and compared to conventional substrates for printed circuit board (PCB) applications.

The new LuVo Board exhibits similar properties to commercially available high‐performance substrates. The main advantage of the LuVo Board is a reduction of manufacturing costs in comparison to conventional substrates, as a highly automated manufacturing process can be employed. Moreover, the LuVo Board exhibits some further advantages: the material is inherently flame resistant and can be thermally shaped after the assembly process.

This paper presents an entirely new thermoplastic substrate, which can be employed in high‐frequency applications. In comparison to standard materials, a further advantage of the thermoplastic substrate is lower production costs.

There is increasing customer demand for materials with low dissipation factors for reduced loss along the traces and low dielectric constants for higher signal propagation speeds. High performance epoxies such as Nelco's N4000‐13, Isola's FR408 and General Electric's GETEK (similar to Matsushita's MEGTRON) have become essential for boards operating in the higher frequency range. For applications at the highest frequencies material choices are very limited. These materials, tailored for high frequency use, have disadvantages – either with their thermomechanical properties or with their processability. Recently, a number of new “high frequency” or “low loss” materials have been introduced by different suppliers. In an overall relatively small but growing market, these materials have to demonstrate their advantages – from an electrical, thermomechanical, processing, fabrication quality and/or cost standpoint when compared to the established materials. This paper compares the thermomechanical performance and fabrication quality of new “high frequency”/“low loss” base materials.

Wheat plants were grown in field plots of 3×3m area. After growth period of two months, the growing plants were sprayed with dimethoate and pirimicarb at the recommended dose. Spraying was repeated after a further 45 days. Plant samples were taken at intervals of zero, three, six, nine, 12 and 15 days after each application. A gradual and continuous degradation of the applied pesticides had taken place in the treated wheat shoots up to the end of the experiment. However, dimethoate showed more residues and persistence rather than pirimicarb. The break down and metabolism of the applied pesticides was correlated with some biochemical changes in the sprayed plants. Sampling dates of three and six days after application were the most critical periods to affect plant metabolism. A decline was noticed in chlorophyll, sugars and carbohydrates, total proteins and RNA content of wheat shoots as a function of the applied pesticides. Free amino acids were accumulated in the sprayed plants, meanwhile the DNA content did not show observable changes as a consequence of the applied pesticides treatment.