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Limitations in microelectronics—II. Bipolar technology
86
WORLD
ABSTRACTS
ON MICROELECTRONICS
AND
RELIABILITY
failures which occurred during tests upon a sample from that population. Comparisons between products based upon such data can be misleading. While use of the Wiebull method is an excellent way of discriminating between the reliability of two or more product populations, this method demands complete details of the sampling life tests, which the would-be user may not have. T h e author offers a method by which the user can approach the Wiebull accuracy if detailed results of the sampling tests are not available.
machine suitable for testing individual custom-designed M O S integrated circuits with up to forty leads, or groups of these circuits (up to fourteen) in the form of functional units in association with reed relays, transformers and discrete components. T h e choice of memory and patching field is discussed, as is a computer program which assists with the preparation of test data. T h e suitability of the tester for either production or laboratory work is also explained.
Classification of reliability tests. K. F. TOM.6.§EK. Microelectron. & Reliab. 11 (1972), p. 361. This paper presents an original mathematical formulation of the basic problems of reliability tests of component parts and systems. This formulation provides a better insight into the different types of reliability testing, the techniques of realization and the methods of evaluation of the results of the tests being involved.
Limitations in microelectronics--H. Bipolar technology. B. HOENEISF2~ and C. A. MEAD. Solid St. Electron. 15 (1972), p. 891. T h e physical phenomena which will ultimately limit miniaturization of planar bipolar integrated circuits are examined. T h e maximum packing density is obtained by minimizing the supply voltage and the size of the devices. T h e minimum transistor size is determined by junction breakdown, punch through and doping fluctuations. For circuits that are fully active the maximum n u m b e r of circuit functions per chip is determined by power dissipation. T h e packing density of read-only memories becomes limited by the area occupied by devices and interconnections. T h e limitations of M O S and bipolar technologies are compared. It is concluded that read-only memories will reach approximately the same performance and packing density with M O S and bipolar technologies, while fully active circuits will reach the highest levels of integration with dynamic M O S or complementary M O S technologies.
Bayesian decision analysis of the hazard rate for a two-parameter Weibull process. K, V. BURY. I E E E Trans. Reliab. R-21, No. 3, August (1972), p. 159. A two-parameter Weibull distribution is assumed to be the appropriate statistical life-model of an engineering device. T h e hazard rate of this device is the relevant quantity in terms of which statistical decisions are to be made. A Bayesian decision model is constructed around a conjugate probability density function for the Weibull hazard rate. Prior, posterior and preposterior analysis of this decision model are discussed. T h e results indicate the rational decision before and after sampling, and permit the optimization of sequential single-item sampling schemes. Such schemes are of particular importance in the reliability testing of high-cost equipment. Selecting inputs to test digital circuits on c o m p l e x IC b o a r d s . D. P. ALLEN and N. P. LYONS. Electronics, July (1972), p. 88. Choosing excitation codes for inputs to locate faults and troubleshoot them requires judicious decisions on the right combination of fixed and pseudorandom signals that can be reproduced exactly for repetitive checks. A tester for MOS integrated circuits. R. N. CONNELLY. Plessey Systems Technology, No. 15 (1972), p. 6. This article describes the development of an automatic
Optical isolators: outlook is bright. L. MATTERA. Electronics, July (1972), p. 103. Lower prices and IC compatibility widen use of photon couplers as data communications interface circuits, relays and limit switches. Good things c o m e in s m a l l packages. B. MITCHELL. Electron. Engng, October (1972), p. 56. Three major factors dictate the reliability of electronic equipmentcomponent parts (including joints and interconnections), design and production. Assuming that equipment manufacturers use components of known or proven quality, equipment reliability is governed entirely by reliability in design and production.
2. RELIABILITY OF C O M P O N E N T S , TUBES, T R A N S I S T O R S A N D ICs Estimating the reliability of electronic tubes with the aid of truncated Hfe tests. J. MACHOVEC. T E S L A Electron., 4 (1972), p. 103. T h e article describes a method for determining the criteria used in estimating the properties of products until the end of their guaranteed life, as based on results measured during the first hours of test working under normal conditions. To determine these criteria the analysis is used of statistical results obtained from currently realized life tests, the course of the respective parameters being described by a set of
equations of predetermined degree. By statistically processing the sets of coefficients of the respective orders the limits of these coefficients are determined, guaranteeing with a predetermined probability that the products will be serviceable at their life end as well. An example of the application to the T E S L A type E88CC electronic tubes is stated.
Avalanche breakdown in silicon diffused junctions. R. M. WAI~ER, JR. SolidSt. Electron. 15 (1972), p. 1303.
WORLD
ABSTRACTS
ON MICROELECTRONICS
AND
RELIABILITY
failures which occurred during tests upon a sample from that population. Comparisons between products based upon such data can be misleading. While use of the Wiebull method is an excellent way of discriminating between the reliability of two or more product populations, this method demands complete details of the sampling life tests, which the would-be user may not have. T h e author offers a method by which the user can approach the Wiebull accuracy if detailed results of the sampling tests are not available.
machine suitable for testing individual custom-designed M O S integrated circuits with up to forty leads, or groups of these circuits (up to fourteen) in the form of functional units in association with reed relays, transformers and discrete components. T h e choice of memory and patching field is discussed, as is a computer program which assists with the preparation of test data. T h e suitability of the tester for either production or laboratory work is also explained.
Classification of reliability tests. K. F. TOM.6.§EK. Microelectron. & Reliab. 11 (1972), p. 361. This paper presents an original mathematical formulation of the basic problems of reliability tests of component parts and systems. This formulation provides a better insight into the different types of reliability testing, the techniques of realization and the methods of evaluation of the results of the tests being involved.
Limitations in microelectronics--H. Bipolar technology. B. HOENEISF2~ and C. A. MEAD. Solid St. Electron. 15 (1972), p. 891. T h e physical phenomena which will ultimately limit miniaturization of planar bipolar integrated circuits are examined. T h e maximum packing density is obtained by minimizing the supply voltage and the size of the devices. T h e minimum transistor size is determined by junction breakdown, punch through and doping fluctuations. For circuits that are fully active the maximum n u m b e r of circuit functions per chip is determined by power dissipation. T h e packing density of read-only memories becomes limited by the area occupied by devices and interconnections. T h e limitations of M O S and bipolar technologies are compared. It is concluded that read-only memories will reach approximately the same performance and packing density with M O S and bipolar technologies, while fully active circuits will reach the highest levels of integration with dynamic M O S or complementary M O S technologies.
Bayesian decision analysis of the hazard rate for a two-parameter Weibull process. K, V. BURY. I E E E Trans. Reliab. R-21, No. 3, August (1972), p. 159. A two-parameter Weibull distribution is assumed to be the appropriate statistical life-model of an engineering device. T h e hazard rate of this device is the relevant quantity in terms of which statistical decisions are to be made. A Bayesian decision model is constructed around a conjugate probability density function for the Weibull hazard rate. Prior, posterior and preposterior analysis of this decision model are discussed. T h e results indicate the rational decision before and after sampling, and permit the optimization of sequential single-item sampling schemes. Such schemes are of particular importance in the reliability testing of high-cost equipment. Selecting inputs to test digital circuits on c o m p l e x IC b o a r d s . D. P. ALLEN and N. P. LYONS. Electronics, July (1972), p. 88. Choosing excitation codes for inputs to locate faults and troubleshoot them requires judicious decisions on the right combination of fixed and pseudorandom signals that can be reproduced exactly for repetitive checks. A tester for MOS integrated circuits. R. N. CONNELLY. Plessey Systems Technology, No. 15 (1972), p. 6. This article describes the development of an automatic
Optical isolators: outlook is bright. L. MATTERA. Electronics, July (1972), p. 103. Lower prices and IC compatibility widen use of photon couplers as data communications interface circuits, relays and limit switches. Good things c o m e in s m a l l packages. B. MITCHELL. Electron. Engng, October (1972), p. 56. Three major factors dictate the reliability of electronic equipmentcomponent parts (including joints and interconnections), design and production. Assuming that equipment manufacturers use components of known or proven quality, equipment reliability is governed entirely by reliability in design and production.
2. RELIABILITY OF C O M P O N E N T S , TUBES, T R A N S I S T O R S A N D ICs Estimating the reliability of electronic tubes with the aid of truncated Hfe tests. J. MACHOVEC. T E S L A Electron., 4 (1972), p. 103. T h e article describes a method for determining the criteria used in estimating the properties of products until the end of their guaranteed life, as based on results measured during the first hours of test working under normal conditions. To determine these criteria the analysis is used of statistical results obtained from currently realized life tests, the course of the respective parameters being described by a set of
equations of predetermined degree. By statistically processing the sets of coefficients of the respective orders the limits of these coefficients are determined, guaranteeing with a predetermined probability that the products will be serviceable at their life end as well. An example of the application to the T E S L A type E88CC electronic tubes is stated.
Avalanche breakdown in silicon diffused junctions. R. M. WAI~ER, JR. SolidSt. Electron. 15 (1972), p. 1303.