In order to succeed against global competition, it is becoming increasingly important for the Fuji Electric Group, which has a wide range of product groups, to use analysis and simulation technologies in each of the stages of R&D, production and market introduction. Analysis technology is being utilized not only to challenge the limits of spatial resolution and microanalysis, but the developers themselves are also implementing particular analyses according to their interests. Moreover, analysis and simulation technologies are being utilized effectively in studying advance reviews, optimization and studying things that cannot be verified at the experimental test. This paper discusses the background and presents an overview of these technologies.

When analyzing minute defects, an effective technique is to prepare a cross-section thin-film sample of the defective area, and then use a transmission electron microscope (TEM) to observe and analyze the sample. A focused ion beam (FIB) processing system is used to prepare cross-section thin-film samples. However, such samples are difficult to prepare if the location of the defect cannot be detected when using the FIB processing system. In this case, it is important to devise some method, such as by repeatedly marking with various observation and analysis systems, so that the defect location will be observable with the FIB processing system.

More advanced bonding technology is required for semiconductor devices, which are trending toward smaller sizes and increased complexity. The technology for performing a detailed analysis of the bonding status is also indispensable. For this reason, the technology for preparing precise cross-section samples is becoming increasingly important. Addressing the difficulty of implementing cross-sectional analyses of flexible and thin-film intermetallic compounds, we have successfully established precision cross-section sample preparation technology utilizing mechanical polishing, microtome, CP and FIB techniques.

Electron beams and X-rays are used in many types of analysis, and in particular, the techniques of using a transmission electron microscope (TEM) to observe microscopic structures and of using X-ray diffraction (XRD) for crystallographic analysis are indispensable for product development. As high performance and high quality of products, analysis of smaller areas and thinner films is being necessary is required, and the combination of multiple analysis techniques is effective to solve such difficult problems. This paper describes the example of crystallographic analysis of magnetic recording media and a SiC epitaxial layer using both TEM and synchrotron radiation XRD.

Fuji Electric has been manufacturing various electronic devices such as semiconductors, magnetic recording media, and organic photo conductors (OPCs). Crystal structure analysis techniques for all these devices have been established, and are being advanced for higher performance. This paper describes the application of in-plane grazing incidence X-ray diffraction which is a powerful technique for the structural analysis of very thin surface layers (of approximately 10nm in thickness), and electron backscattering diffraction profile (EBSP) which is effective for visualizing submicron-size crystal structures.

This paper describes a synchrotron radiation grazing-incidence X-ray diffraction method for quantitative analysis of stacking faults (SF), which cause a decrease in magnetic anisotropy in perpendicular magnetic recording media. This new method uses reciprocal space mapping, in which the SF concentration can be estimated from the broadening of diffraction peaks. Because the shape of the peak is also affected by crystal quality, the quantitative evaluation of SFs had been difficult. Using this new method, we found that the Pt concentration should be less than 15 at% in order to avoid an increase in SF concentration in the CoPtCr-SiO_{2<>/sub media.}

Low-voltage circuit breaker cases are molded products, and it is important that they be designed in consideration of the pressure rise from atmospheric pressure to several MPa during the extremely short time interval of short-circuit current breaking, which ranges from approximately several milliseconds to 10ms. Fuji Electric is working to establish strength analysis technology for molded products. Using the case-internal pressure distribution, obtained through advance verification testing using a modeled device, as an input condition, and by also modeling the screws that engage partitioned cases, Fuji Electric recently established technology for analyzing, in a batch process, the strength of an entire case.

The strength of molded cases that house low-voltage circuit breakers, which protect distribution systems from damage when a short circuit fault occurs, must be verified in order to ensure sufficient strength to withstand the rise in internal pressure to 1MPa or above due to the arc energy generated during the breaking of a large current. Also, because the breaking unit reaches an extremely high temperature, soot and metallic particles are generated and adhere to the inner walls and to other components, and thus some measure must be implemented to prevent a decrease in the withstand voltage performance. Using computational fluid dynamics that take into account the heat generated by the arc and wear of the physical structure, Fuji Electric has evaluated the internal pressure of the circuit breaker and the behavior of the generated byproducts, and this paper reports a summary thereof.

The main focus of efforts to reduce the energy consumption of freezers and refrigerators is to raise the efficiency of the cooling system. The challenges in raising efficiency involve increasing the efficiency of the heat exchanger, and in particular, increasing the thermal conductivity of the heat exchanger's fins. Also, there is the problem of worsening pressure loss due to condensation and frost formation in the heat exchangers for freezers and refrigerators. Thus, we have devised a heat exchanger that uses a vortex generator capable of realizing less pressure loss and higher thermal conduction, and by optimizing the shape and layout of the vortex generator, have established fluid flow and heat transfer simulation technology capable of clearly visualizing the flow of air on the fins and the heat transfer phenomenon.

In order to help prevent global warming, CFC-free vending machines that use the natural coolant of CO₂ are being developed as environmentally- friendly vending machines. To evaluate the increasing number of refrigeration models and to boost developmental efficiency, there is a need for refrigeration performance simulators for vending machines capable of using CO₂ coolant. We have formalized the evaluation characteristics according to coolant performance and CO₂ refrigerant cycle, and have established a new computation algorithm to develop a refrigerant cycle simulator capable of computing refrigerator performance. This paper describes those results.

The power module inside a general-purpose inverter is cooled with an extremely simple and low-cost structure consisting of a cooling fin and a cooling fan, and the cooling performance strongly affects the structure and reliability of the inverter device. As part of our efforts to improve the performance of power module cooling, this paper introduces an example in which we apply thermo-fluid simulation technology to optimize the flow of cooling air and the layout of components.

Two examples of simulation with chemical reactions, wet etching of a silicon wafer and the deposition of polysilicon with a chemical vapor deposition (CVD) reactor, are described in this paper. In the case of wet etching, the concentration of important chemical etchant HNO₃ was computed based on a free surface flow, and good agreement was obtained between the computed etching rates and experimental results. In the case of a CVD reactor, nine reactants and eighteen elementary reactions were taken into account. The quantitative similarity between computed and experimental growth rates of polysilicon proves computational fluid dynamics with chemical reactions including thermal and material flow to be an effective method for understanding the phenomena in CVD reactors.

The production of metal-cast objects, and especially die-cast products, faces the challenges of reducing quality-related problems of pores, shape deformity and the like from improper casting, ramping-up of mass-production within a short time period and realizing further cost reductions. Indispensable to success in the above are product design that takes into consideration the manufacturability during the developmental stage, and the formulation of a casting plan based on scientific principles. This paper describes the effect of applying casting simulation technology, the functions of which have improved remarkably in recent years, to the product development and mass-production of a diecast aluminum heat sink for use in a general-purpose inverter.

Because of the effects of thermal stress and centrifugal force at the brazed section of a rotor coil in a power generator during operation, highly reliable bonding is required. Presently, the quality of a brazed section is verified according to a destructive inspection with a spare coil and visual inspection by a skilled worker. Aiming to improve the quality and stability of brazed sections, Fuji Electric has advanced the development of an ultrasonic non-destructive inspection system for brazed sections. This paper presents an overview of the inspection system.

From the perspective of protecting the global environment, efforts to avoid using hazardous materials in electronic devices are being considered actively. Beginning with the RoHS directive in the European Union, restrictions on the use of such hazardous materials are also spreading to China, South Korea and throughout the world. Fuji Electric is aggressively pursuing the development of environmentallyconscious materials, and of the materials in compliance with these regulations, and this paper discusses the development of reactive nonhalogen flame retardant technology for molding resin, and lead-free soldering materials among these materials.