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Small sized plated through connections in flexible cables
Microelectronicsand Reliability,Vol. 16~pp. 641 to 660. PergamonPress,1977. Printedin Great Britain
WORLD ABSTRACTS ON MICROELECTRONICS AND RELIABILITY The abstracts below are given in reasonable detail where necessary so that an appreciation can be made of the coverage of the article. They are probably the most comprehensive detailed abstracts published in these two fields and in general are all of articles published within the last 12 months. They are classified into the following sections. 1. 2. 3. 4. 5. 6. 7. 8. 9.
Reliability--General. Reliability of Components, Tubes, Transistors and ICs. Circuit and Systems Reliability, Maintenance and Redundancy. Microelectronics--General. Microelectronics Design and Construction. Microelectronic~Components, Systems and Equipments. Semiconductor Integrated Circuits, Devices and Materials. Thick- and Thin-Film Components, Hybrid Circuits and Materials. Electron, Ion and Laser Beam Techniques.
1. R E L I A B I L I T Y - - G E N E R A L "Quality matters" A. J. GILBERT. Electron. Power p. 409 (May 1977). Quality matters to an organisation: without it is unlikely to retain customers; bad quality is expensive and tan erode substantial amounts of profit. Without good quality, in its broadest sense, the individual and the company are at risk in the eyes of the law.
Controlling potential static charge problems. PHIL KOHLHAAS. Electron. Prod. p. 155 (June 1977). Thousands of dollars are spent on clean rooms, wafer scrubbers and laminar flow hoods to control contamination. Extreme care is
taken to package and protect devices from physical shock. But only a relatively few companies provide their product with complete static protection. Most companies settle for partial static control and a few companies provide no protection at all. While some skepticism existed one or two years ago as to whether static charge is responsible for high failure rates, it is now an accepted fact that some MOS devices can be destroyed by less than 100 V of static charge. Personnel handling the devices can easily hold over 10,000 V of static charge.
2. RELIABILITY OF COMPONENTS, TUBES, TRANSISTORS AND ICs The reliability of thick film capacitors and crossovers. W. R. BRATSCHUN,P. G. EVERETT and T. J. GABRYKEWICZ. Proc. Electron. Components Conf. Arlington, Va., May 16-18, 1977. p. 161. This paper describes the theoretical basis for accelerated life testing of thick film capacitors and crossovers, the mechanism of the generated failures, the experimental testing procedures, and the experimental data. Conclusions are given that thick film capacitors and crossovers may be made with high reliability but considerations must be given to processing, the quality of the dielectric layer, the type of electrode, and the use of a glass sealing layer. Four types of dielectric systems were studied: (1) ferroelectric barium titanate, (2) ferroelectric niobate glass-ceramic, (3) non-ferroelectric glass-ceramic, and (4) an alumina/glass mixture. The types of electrodes were silver-palladium, silver-platinum, and 100~o silver. Both capacitors and crossovers with and without glass sealing layers were studied. Data is presented on accelerated load life testing and is used to project failure rates at field operating conditions. Failure mechanisms in beam lead semiconductors. U. C. BROWN and, J. R. SIM. Proc. Electron. Components Conf. Arlington, Va., May 16-18, 1977. p. 188. Hybrid microcircuits (HMCs) designed for the Energy Research and Development Administration by Sandia Laboratory in Albuquerque, New Mexico, and manufactured by the Kansas City Division of the Bendix Corporation use beam lead devices as active components. The HMCs consist of sputtered tantalum-nitride (Ta2N) resistors and evaporated 641
chromium-gold (Cr-Au) conductors on alumina substrates with applique components and thermocompression bonded ribbons, lead frames, fine wires, and beam lead devices. During recent testing of HMCs for a new program, failures of beam lead devices (BLDs) resulted in unacceptable yields and increased rework. These BLD failures showed up primarily as increased leakage failures, intermittent failures that repeated on a random basis, and in worst cases, as direct device shorts.
Small sized plated through connections in flexible cables. GEORGE VOIDA. Proc. Electron. Components Conf. Arlington, Va., May 16-18, 1977. p. 290. The reliability of plated through holes in flexible cables and measurements to assess their quality are described in this study. PTH's as small as 0.33 mm in diameter were produced in 50/~m thick Kapton insulation. To determine the stability of the PTH's, test panels were exposed to flexure, 150°C aging, temperature shock, humidity, mechanical shock and vibration, and altitude testing. The current carrying capacity and stability to soldering and unsoldering of the PTH's were also determined. Series resistance measurements were made to determine the quality of PTH's before and after the environmental exposures. Copper thickness of the PTH's measured by the microhm resistance method agreed within about 50~ with the corresponding thicknesses determined by cross-sectioning. Results in the present study confirm that flexcircuits with small size PTH's can be very reliable for use in complex electronic assemblies and in weapon applications.
WORLD ABSTRACTS ON MICROELECTRONICS AND RELIABILITY The abstracts below are given in reasonable detail where necessary so that an appreciation can be made of the coverage of the article. They are probably the most comprehensive detailed abstracts published in these two fields and in general are all of articles published within the last 12 months. They are classified into the following sections. 1. 2. 3. 4. 5. 6. 7. 8. 9.
Reliability--General. Reliability of Components, Tubes, Transistors and ICs. Circuit and Systems Reliability, Maintenance and Redundancy. Microelectronics--General. Microelectronics Design and Construction. Microelectronic~Components, Systems and Equipments. Semiconductor Integrated Circuits, Devices and Materials. Thick- and Thin-Film Components, Hybrid Circuits and Materials. Electron, Ion and Laser Beam Techniques.
1. R E L I A B I L I T Y - - G E N E R A L "Quality matters" A. J. GILBERT. Electron. Power p. 409 (May 1977). Quality matters to an organisation: without it is unlikely to retain customers; bad quality is expensive and tan erode substantial amounts of profit. Without good quality, in its broadest sense, the individual and the company are at risk in the eyes of the law.
Controlling potential static charge problems. PHIL KOHLHAAS. Electron. Prod. p. 155 (June 1977). Thousands of dollars are spent on clean rooms, wafer scrubbers and laminar flow hoods to control contamination. Extreme care is
taken to package and protect devices from physical shock. But only a relatively few companies provide their product with complete static protection. Most companies settle for partial static control and a few companies provide no protection at all. While some skepticism existed one or two years ago as to whether static charge is responsible for high failure rates, it is now an accepted fact that some MOS devices can be destroyed by less than 100 V of static charge. Personnel handling the devices can easily hold over 10,000 V of static charge.
2. RELIABILITY OF COMPONENTS, TUBES, TRANSISTORS AND ICs The reliability of thick film capacitors and crossovers. W. R. BRATSCHUN,P. G. EVERETT and T. J. GABRYKEWICZ. Proc. Electron. Components Conf. Arlington, Va., May 16-18, 1977. p. 161. This paper describes the theoretical basis for accelerated life testing of thick film capacitors and crossovers, the mechanism of the generated failures, the experimental testing procedures, and the experimental data. Conclusions are given that thick film capacitors and crossovers may be made with high reliability but considerations must be given to processing, the quality of the dielectric layer, the type of electrode, and the use of a glass sealing layer. Four types of dielectric systems were studied: (1) ferroelectric barium titanate, (2) ferroelectric niobate glass-ceramic, (3) non-ferroelectric glass-ceramic, and (4) an alumina/glass mixture. The types of electrodes were silver-palladium, silver-platinum, and 100~o silver. Both capacitors and crossovers with and without glass sealing layers were studied. Data is presented on accelerated load life testing and is used to project failure rates at field operating conditions. Failure mechanisms in beam lead semiconductors. U. C. BROWN and, J. R. SIM. Proc. Electron. Components Conf. Arlington, Va., May 16-18, 1977. p. 188. Hybrid microcircuits (HMCs) designed for the Energy Research and Development Administration by Sandia Laboratory in Albuquerque, New Mexico, and manufactured by the Kansas City Division of the Bendix Corporation use beam lead devices as active components. The HMCs consist of sputtered tantalum-nitride (Ta2N) resistors and evaporated 641
chromium-gold (Cr-Au) conductors on alumina substrates with applique components and thermocompression bonded ribbons, lead frames, fine wires, and beam lead devices. During recent testing of HMCs for a new program, failures of beam lead devices (BLDs) resulted in unacceptable yields and increased rework. These BLD failures showed up primarily as increased leakage failures, intermittent failures that repeated on a random basis, and in worst cases, as direct device shorts.
Small sized plated through connections in flexible cables. GEORGE VOIDA. Proc. Electron. Components Conf. Arlington, Va., May 16-18, 1977. p. 290. The reliability of plated through holes in flexible cables and measurements to assess their quality are described in this study. PTH's as small as 0.33 mm in diameter were produced in 50/~m thick Kapton insulation. To determine the stability of the PTH's, test panels were exposed to flexure, 150°C aging, temperature shock, humidity, mechanical shock and vibration, and altitude testing. The current carrying capacity and stability to soldering and unsoldering of the PTH's were also determined. Series resistance measurements were made to determine the quality of PTH's before and after the environmental exposures. Copper thickness of the PTH's measured by the microhm resistance method agreed within about 50~ with the corresponding thicknesses determined by cross-sectioning. Results in the present study confirm that flexcircuits with small size PTH's can be very reliable for use in complex electronic assemblies and in weapon applications.