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Relay failure analysis techniques
250
WORLD A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
include solid carbon resistors, carbon diaphragm resistors, winding resistors, potentiometers and capacitors. Tropical weather, desert weather, cold zone weather, upper atmosphere weather and mechnical environment conditions are investigated. Production automation and miniaturization are briefly discussed as means of increasing component reliability. *Packaging and reliability in integrated circuits. R. L. COREN and T. J. MATCOVICH,1968 Prod. Ass. Conf. Tech. Exhibition, Long Island, N.Y., June 7-8, 1968, Transactions, p. 137. Reliability considerations in solid state devices and integrated circuits are discussed, along with some present-day interconnection techniques and a packaging scheme to improve IC reliability. The greatest limitation on IC reliability is considered to be in the lead connections to the outside world, and the use of hybrid circuits is considered a practical means of overcoming the limitation. Packaging schemes have been devised for use with large hybrid systems, and one such scheme involves an intimate stacking of circuit boards and has a multilayer ceramic board. In addition to three-dimensional stacking and high density, this scheme has short lead lengths, all interconnections in a single module, standardization of modules and external package, and ruggedness of the complete package.
*Physical analysis of stress testing for failure of electronic components. C. F. Koot, IEEE Trans. Reliab. RI7, June (1968), p. 80. Starting with an assumption concerning the type of physical process causing failure and an assumption concerning the random distribution of components with respect to a failure threshold, cumulative distribution functions in time, temperature, and voltage are derived. These cumulative distribution functions are identical to each other if the random variables are certain functions of time, temperature, or voltage, thus showing the equivalence of time, temperature and voltage as stresses. The cumulative distribution function in time is the familiar log-normal function. If it is known that the assumed physical process is the only one causing failure, then one can rigorously replace time by temperature or voltage. However, it is demonstrated that in an accelerated test--i.e. a test in which time is replaced by another stress such as temperature--one can never be sure that another process will not be predominant at longer times; thus, one can never make a certain extrapolation to longer times. One might be able to circumvent this difficulty by having a thorough knowledge of the physics, chemistry and metallurgy of the possible failure processes in the component.
*Relay failure 8n~lysis techniques. J. J. LOMBARD,JR., 16th Ann. Nat. Relay Conf., Oklahoma State University, Stillwater, April 23, 24 (1968), Proceedings, p. 11-1 (Paper 11: A68-28188). Detailed description of a step-by-step procedure for failure analysis of relays. An important feature is the incorporation of state-of-the-art analytical techniques into the test sequence. One of the most significant techniques employed is X-ray vidicon analysis. Another teclmique is gas chromatography. This procedure is designed so that all the nondestructive tests are performed first. This allows causes of failure to be traced to an electrical, mechanical, or seal defect without destruction of the relay. The destructive techniques are then employed to positively identify the failure mechanism.
*Testing high reliability relays by use of automatic equipment. C. C. BATESand J. R. GUTH, 16th Ann. Nat. Relay Conf., Oklahoma State University, Stillwater, April 23, 24 (1968), Proceedings, p. 9-1. Design of a fully automated relay tester is described, along with its use as a diagnostic tool and product acceptance tester for the procurement of high reliability relays. Most of the control circuitry for the tester uses solid state devices even though over 100 relays are used in a test. Measurement techniques used are described for coil resistance, contact resistance, insulation resistance and dielectric strength, and function time. Functional elements of the test system include the system programmer, switching matrix and data recorder; and except for the temperature chamber, typewriter and IBM punch, all of the equipment is housed in a single cabinet that has a master control panel. A typical set of electrical function data for a single unit is shown, and codes for interpreting the numerical output are defined. Dropout current characteristic during the mechanical life of two types of crystal case relays is illustrated, and histogram reductions of electrical parameters are included.
WORLD A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
include solid carbon resistors, carbon diaphragm resistors, winding resistors, potentiometers and capacitors. Tropical weather, desert weather, cold zone weather, upper atmosphere weather and mechnical environment conditions are investigated. Production automation and miniaturization are briefly discussed as means of increasing component reliability. *Packaging and reliability in integrated circuits. R. L. COREN and T. J. MATCOVICH,1968 Prod. Ass. Conf. Tech. Exhibition, Long Island, N.Y., June 7-8, 1968, Transactions, p. 137. Reliability considerations in solid state devices and integrated circuits are discussed, along with some present-day interconnection techniques and a packaging scheme to improve IC reliability. The greatest limitation on IC reliability is considered to be in the lead connections to the outside world, and the use of hybrid circuits is considered a practical means of overcoming the limitation. Packaging schemes have been devised for use with large hybrid systems, and one such scheme involves an intimate stacking of circuit boards and has a multilayer ceramic board. In addition to three-dimensional stacking and high density, this scheme has short lead lengths, all interconnections in a single module, standardization of modules and external package, and ruggedness of the complete package.
*Physical analysis of stress testing for failure of electronic components. C. F. Koot, IEEE Trans. Reliab. RI7, June (1968), p. 80. Starting with an assumption concerning the type of physical process causing failure and an assumption concerning the random distribution of components with respect to a failure threshold, cumulative distribution functions in time, temperature, and voltage are derived. These cumulative distribution functions are identical to each other if the random variables are certain functions of time, temperature, or voltage, thus showing the equivalence of time, temperature and voltage as stresses. The cumulative distribution function in time is the familiar log-normal function. If it is known that the assumed physical process is the only one causing failure, then one can rigorously replace time by temperature or voltage. However, it is demonstrated that in an accelerated test--i.e. a test in which time is replaced by another stress such as temperature--one can never be sure that another process will not be predominant at longer times; thus, one can never make a certain extrapolation to longer times. One might be able to circumvent this difficulty by having a thorough knowledge of the physics, chemistry and metallurgy of the possible failure processes in the component.
*Relay failure 8n~lysis techniques. J. J. LOMBARD,JR., 16th Ann. Nat. Relay Conf., Oklahoma State University, Stillwater, April 23, 24 (1968), Proceedings, p. 11-1 (Paper 11: A68-28188). Detailed description of a step-by-step procedure for failure analysis of relays. An important feature is the incorporation of state-of-the-art analytical techniques into the test sequence. One of the most significant techniques employed is X-ray vidicon analysis. Another teclmique is gas chromatography. This procedure is designed so that all the nondestructive tests are performed first. This allows causes of failure to be traced to an electrical, mechanical, or seal defect without destruction of the relay. The destructive techniques are then employed to positively identify the failure mechanism.
*Testing high reliability relays by use of automatic equipment. C. C. BATESand J. R. GUTH, 16th Ann. Nat. Relay Conf., Oklahoma State University, Stillwater, April 23, 24 (1968), Proceedings, p. 9-1. Design of a fully automated relay tester is described, along with its use as a diagnostic tool and product acceptance tester for the procurement of high reliability relays. Most of the control circuitry for the tester uses solid state devices even though over 100 relays are used in a test. Measurement techniques used are described for coil resistance, contact resistance, insulation resistance and dielectric strength, and function time. Functional elements of the test system include the system programmer, switching matrix and data recorder; and except for the temperature chamber, typewriter and IBM punch, all of the equipment is housed in a single cabinet that has a master control panel. A typical set of electrical function data for a single unit is shown, and codes for interpreting the numerical output are defined. Dropout current characteristic during the mechanical life of two types of crystal case relays is illustrated, and histogram reductions of electrical parameters are included.