The bidirectional operation of lines with TTL circuits

The bidirectional operation of lines with TTL circuits

178 World Abstracts on Microelectronics and Reliability contaminated with Na. A statistical method is used for measuring the breakdown probability a...

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178

World Abstracts on Microelectronics and Reliability

contaminated with Na. A statistical method is used for measuring the breakdown probability as a function of log time and applied field. It is shown that three time regions of breakdown can be explained respectively in terms of silicon surface defects, ion emission from the metal interface, and lateral ion diffusion at the silicon interface.

square of the power supply voltage. Dr. Ing Lubomir Cergel explains the dissipation capabilities of standard C M O S packages and suggests a few thermal management lips.

The structure of incomplete destructive breakdown spots in thin polymer films. S. SAPIEHA,W. JABLONSK1and M. KRYSZEWSKL Electrocomponent Science and Technology I, 65

(I 975). High voltage operation of mctallized tilm capacitors leads to electrical spark breakdown in pockets of gas trapped within the sealed capacitor unit. A simple picture of gas discharge processes in the capacitor is used to identif3. the role played by electric discharges in the deterioration and ultimate failure of capacitors under accelerated life test.

(1974). Experimental observations are given on the structure of breakdown spots in thin layers of polystyrene and polybenzene obtained by a glow discharge technique. The levels of energy associated with different types of breakdown are identified and it is shown that within the range of breakdown energy level, lower than 10 5j, with energy levels greater than 5 x 10- 3 joules, single hole, self-healing breakdown with complete destruction of the inner morphological channel structure occurs. The nature of the breakdown is discussed in electrical and electron microscopy terms.

Reliability study checks moisture levels in ICs. MARTIN MAmETTA. Electronics p. 29 (April 1 1976). Leakage in a hermatic package. For high-reliability integrated circuits that's been an industry-wide no-no, although some leakage always exists. But leakage may no longer be such a taboo. Now being launched is a series of experiments on the effects of moisture on integrated circuitry. By correlating leakage rates with moisture content, they may show that lCs can tolerate some leakage after all.

Thermal design considerations in CMOS circuits. Dr. INCJ LUP,OMm CERC,t!L. Electronic Eng. p. 56 (April 1976). Complementary metal oxide semiconductor devices consume almost negligible power in the quiescent state; however, their power consumption increases in direct proportion to the capacitive load, the operating frequency, and the

On the damage to metallized film capacitors caused by electrical discharges. J. W. BURGESS, R. T. BILSON and N F. JACKSON. Electrocomponem Science alld ~'chnology 2, 201

Does parts screening really pay off. ROBERT SCHI/NIIig. Et,aluation En(]ineerinfl p. 20 (Nov./Dec. 1975). If one is to suggest screening as a cost effective measure in production, the cost of screening out a failure must be less than "'troubleshooting" out a failure on the production line. The "Cost per Reject" is a screening efficiency figure to catch the failure before it is installed in the equipment being manufactured. An analysis was made on data representing approximately 1300 lots of various semiconductors t~ establish the average reject rate for each screening test.

The bidirectional operation of lines with TTL circuits. V. KOHLER. Nachrichtentechnik Elektronik 25, (11) 421 (1075). (In German). The load conditions of bidirectional lines are investigated when operate with TTL circuits. As the necessary parallel connexion at the output is only permitted with gates having an open collector, the limits within which it is confined are calculated and the advantages and inconveniences are mentioned. For practically real cases possibilities are shown to increase the number of units to be connected. To conclude, realizations known of bidirectional lines and interface circuits usual at present are discussed

3. CIRCUIT AND SYSTEMS RELIABILITY, MAINTENANCE AND REDUNDANCY Noise and control problems. Designing reliability into equipment having power semiconductors. Part 1. ALWXANDE~ KUSKO, THORLEIF KNUTRUD and JOHN J. CAIN. Electronics p. 111 (March 1976). This first part of the series begins by dealing with a problem that invades every aspect of electronic power-circuit design, electrical noise. Then the article concentrates on reliability in the control and logic portion of rectifiers, inverters and choppers that make up most power semiconductor equipment. Particular points of discussion are feedback control circuits, firing-circuit control, abnormalities in control signals, and the effects of firing circuits on thyristors. The second article, which will appear in the March 18 issue, will address the problems of the power semiconductor circuits themselves. To be considered highly reliable, industrial power semiconductor equipment must operate without failure or malfunction for 10,000 hr. That means five years of eighthours-a-da~ operation or one year of continuous operation. Very high reliability is the classification given to equipment that last 100,000 hr without failure. But the equipment must include redundant subsystems wherever a single subsystem turns out to have a lower reliability rating.

Designing reliability into power circuits. Part 2. ALEXANDER KUSKO, THORLEIF KNUTRUD and JOHN J. CAIN. Electronics p. 101 (March 1976). Reliability problems in power-semiconductor equipment are tackled in the same manner as any good circuit design select o p t i m u m components based

on worst-case conditions, than back off to a cosl-vsperformance selection with which you can live. With power equipment, this process must be carried out once for the control and logic and again for the power circuit.

Reliability of space systems. K. R. RAMGOPAL and V. N. PUROItlT. The QR Journal, India p. 15 (Jan. 1976). In this article an attempt is made to give a comprehensive review of reliability considerations in space systems, without attempting any serious discussion on mathematical modelling and the like. However, important aspects like. dcsign constraints, design reviews, reliability improvement techniques, part screening and derating, reliability tests, failure analysis, etc., have been discussed bringing out the outstanding features and environmental constraints of space systems. With special reference to "'Aryabhata" the first Indian Satellite, specimen reliability sensitivity calculations are presented along with computer simulation results.

The problem of testing to MIL-STD-781B. R. W. Bkow~,. Electronic Production p. 35 (Dec. 1975/Jan. 1976). One specification which the M R C A (multi-role combat aircraftl contract has highlighted in recent years is MIL-STD-781B. The purpose of applying the inherent engineering standards was to improve reliability and to guarantee, as ihr as possible, M T B F (mean time between failurel ratings hitherto unobtained. Such standards not only providc a very reliable fighting vehicle but effccl enormous maintcn-