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A highly manufacturable microelectromechanical systems (MEMS) probe card was developed by using flipchip bonding technology, which is applicable to large area array bonding ranging from 2- to 8-in substrates. A cantilever-type probe structure for an actual device was electroplated with nickel--cobalt and was bonded with nickel bump, which anchored on the ceramic substrate. Gold-tin (AuSn) was used as the material of flipchip bonding between the cantilever beam and bump. Flipchip bonding itself is not a new technology, but combining it with a MEMS probe card is a novel technique in large area bonding because of the high reflow temperature (280[degrees]C, [Au.sub.80][Sn.sub.20]). Various parallelism bonding processes were used to find the best bonding method. The MEMS probe card was designed to achieve a deflection of 50 [micro]m when 2 gram force (gf) was applied and to keep elasticity up to a deflection of 150 [micro]m. The specification of the probe card was for actual 12-in dynamic random access memory testing. The measured average contact force was 2.04 gf at a 50-[micro]m overdrive. In addition, mechanical and electrical characteristics were also suitable for the actual device test. Index Terms--Electroplating, eutectic solder, flipchip bonding, microelectromechanical systems (MEMS) probe card.

High voltage pulsed power supply using IGBT (Insulated Gate Bipolar Transistor) stacks and pulse transformer for plasma source ion implantation is proposed. To increase voltage rating, twelve IGBTs are used in series at each IGBT stack and a step-up pulse transformer is utilized. To increase the current rating, the proposed system makes use of synchronized three pulse generator modules composed of diodes, capacitors and IGBT stacks. The proposed pulsed power supply uses semiconductor switches as main switches. Hence, the system is compact, and has semi-infinite lifetime. In addition, it has high flexibility in parameters such as voltage magnitude (10-60 kV), pulse repetition rate (PRR) (10-2000 pps), and pulse width (2-5 [micro]S). Index Terms--Pulsed power supply, IGBT stack, semiconductor switch.

High voltage Marx generator implementation using IGBT (Insulated Gate Bipolar Transistor) stacks is proposed in this paper. To protect the Marx generator at the moment of breakdown, AOCP (Active Over-Current Protection) part is included. The Marx generator is composed of 12 stages and each stage is made of IGBT stacks, two diode stacks, and capacitors. IGBT stack is used as a single switch. Diode stacks and inductors are used to charge the high voltage capacitor at each stage without power loss. These are also used to isolate input and high voltage negative output in high voltage generation mode. The proposed Marx generator implementation uses IGBT stack with a simple driver and has modular design. This system structure gives compactness and easiness to implement the total system. Some experimental and simulated results are included to verify the system performances in this paper. Index Terms--Pulsed power supply, IGBT stack, AOCP, Marx generator.

A compact pulsed high-voltage generator has been developed for applications in pulsed gas discharges. Its operation principle is based on inductive energy storage and it uses a static induction thyristor as the opening switch. It is capable of generating pulsed high voltage of ~15 kV with pulse width of ~200 ns for load resistance of 1 k[ohms]. This generator can be operated at repetition rate as high as 50 kHz if it is driven directly by 200 V power supply and is cooled by transformer oil. It can also be driven by a 12 V car battery through a chopper circuit, while operating at repetition rate of 2 kHz. In this case, an overall energy efficiency of ~40 % has been obtained. Index Terms--Pulsed power systems, power electronics, pulse generation, power semiconductor switches.

We investigated the foundations for high-frequency vacuum electron devices experimentally, with emphasis on deep etch X-ray lithography: lithographie, galvanoformung, abformung (LIGA) to fabricate a miniaturized interaction circuit and a photonic crystal (PC) resonator to excite a stable high-order mode. The successful operation of a LIGA-fabricated folded-waveguide traveling-wave tube was reported. From such physical considerations as Debye length and photonic band gap, we proposed a reflex klystron adopting a cold cathode and a PC resonator. Index Terms--Debye length, deep etch X-ray lithography: lithographie, galvanoformung, abformung (LIGA), photonic crystal (PC) resonator, terahertz.

This paper investigates the applicability of information theory to predicting operator performance in diagnosis tasks at nuclear power plants (NPPs). Some general descriptions about diagnosis tasks in a main control room (MCR) are provided and information theory conventionally used in the studies of human information processing is briefly reviewed. Then, as an alternative to classical information theory, this paper proposes a method to quantify the cognitive information flow of diagnosis tasks, integrating a stage model (a qualitative approach) with information theory (a quantitative approach). An information flow model is developed based on operating procedures and quantified using Conant's model. Finally, three experiments were conducted to evaluate the effectiveness of the proposed approach to predicting human performance, especially average diagnosis time. The results of two experiments show that subjects' diagnosis time has a proportional relationship to the quantified information flow. The other investigated operator performance variation in terms of accuracy under system-paced information presentation. As a result of the third experiment, subjects showed better performances in a specific range of information rate, compared with in other ranges. Index Terms--Diagnosis task, information flow, information theory, operator performance, workload.

Unity power factor zero-voltage-switched ac-to-dc converters with an active filter are proposed. The line voltage is supplied to ac-to-dc converter.s through the rectifier circuit with an input filter, to reduce high-frequency ripple components. The line current is almost synchronized to the line voltage, due to the low impedance of the input filter. The forward zero-voltage-switched multiresonant converters (ZVS-MRC's) are utilized for high-frequency operation and lossless switching. An active filter is introduced to minimize the twice line-frequency ripple component of the output voltage without large-size passive filters. Experimental results show that the proposed scheme gives good steady-state performances of the ac-to-dc converters. Index Terms - Active filter, unity power factor, ZVS-MRC's.