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A system for an automatic detection of defects of semiconductor masks and printed circuit boards
352
World Abstracts on Microelectronics and Reliability
Parts, Hybrids, Packaging PHP-13, {3) 318 (Sept. 19771. Scanning electron microscopy was employed to characterize the structure of the soft-soldered .joints in Si power transistors (type 2N3055h which failed electrically during thermal cycling. Cracks were observed in the soldered joint of many failed devices. Crack propagation seems to be accelerated by the presence of voids in the joint region. The importance of the reactions between the Ni layers and Sn of the solder also affects the long-term reliability of the devices. Fractographs obtained from the failed devices reveal ductile flacture of the soft solder as well as creep or fatigue failure of the solder at the elevated temperature. Based on the structural studies of both failed and uncycled devices, some possibilities for improving device performance are discussed.
Drift of the breakdown voltage in p n junctions in silicon (walk-out). J. F. VERWEV, A. HERINGA. R. Dr WERDT and W. v. D. HOFSTAI). Solid-St. Electron. 20, 689 (1977). A quantitative model for the time behaviour of the walk-out phenomenon in planar p n junctions is given. The injection of hot carriers into SiO2 and subsequent trapping of part of them is assumed to be the origin of the walk-out. The model is found to be in reasonable agreement with the experimental results on both p + n and n ~ p junctions. The parameters in the model are discussed in relation with the experiments. Integrated circuit testing. MARK R. BARBER and ALFRED ZACHARtAS. Bell Labs Rec. p. 125 (May 1977). The process has been streamlined by computer simulation of integratedcircuit operation, simplified software and an efficient production-line setup.
EBIC--a valuable tool fiw semiconductor evaluation and failure analysis. JAMESR. BEALL. I 5th /t. Proc. Reliab Phys. IEEF,. Nevada. p. 61 11977). The Electron Beam Induced Current or EBIC mode of SEM operation is a powerfld tool for analyzing and evaluating semiconductor devices. The EBIC mode may surpass other SEM operating modes in value. EBIC provides the capability for measuring subsurthce electrical and physical parameters withottt mechanical damage to the surface. Semiconductor diffusions provide a unique quality m separating beam induced electron-hole carriers for imaging or measurement. The procedure is straightforward and utilizes a basic SEM having the capability for sample current imaging. For most applications it is not necessary to remove glass passivation or specially prepare the specimen surface. A familiarity with the mechanics of electron beam interactions with solid surfaces provides the basis for EBIC applications. Electrical degradation, due to electron beam irradiation damage, dictates that EBIC applications be limited to sample evaluation or failure analysis.
A system for an automatic detection of defects of semiconductor masks and printed circuit boards. ZmO'qEW M. \Vo.u Ik. E/c(t¢,,, le~hwd. 10, (4) 95 (1977).This paper presents a principle, an algorithm and a hardware system for an automatic detection of defects of PC boards and semiconductor masks. Results of the defect detection process are presented. Defects are detected independently of positions and rotations of examined objects. A dimensional control of particular regions on examined objects is possible. The systent does not treat an image edge uneveness in its digital representation as a defect. A hardware system may be a realtime operating one.
3. CIRCUIT AND SYSTEMS RELIABILITY, MAINTENANCE AND REDUNDANCY Design of self-checking and fault tolerant microprogrammed controllers. IAN WILLIAMSON. Radio Electron. Engr 47, (10) 449 (October 1977). A realization of a self-checking and fail-safe programmable controller which uses a new control memory organization to give a simPle and elegant implementation is described. Using this self-checking controller as an example, a new approach to fault-tolerant design referred to as Dual-Fail-Safe (DFS) is presented which utilizes two self-checking modules. The resulting fauR-tolerant system is shown to be less costly and significantly more reliable than a conventional Triple-Modular-Redundancy (TMR) system.
of items failing in each inspection period and are called grouped data. This paper presents statistical methods for reliability measurement and demonstration from grouped data on items from an exponential life distribution. The maximum likelihood method is used to estimate mean life; tables are given for optimum inspection times. A new statistical (demonstration) test for mean life is locally most powerful and is simpler than the test based on the maximum likelihood estimate. Tables for this test are provided. These tests also apply to a Weibull distribution with known shape parameter.
Combining diagnosis and emulation yields fast fault-finding. LAURENCE BADAGLIACCA and ROBERT CATTERTON. Electronics p. 107 (10 November 1977). Signature analysis and in-circuit emulation via microprocessor socket give test instrument powerful troubleshooting capabilities.
Markov processes for reliability analyses of large systems. IOANNIS A. PAPAZOGLOU and ELIAS P. GYFTOPOULOS. IEEE Trans. Reliab. R-26./3/232 (August 19771. This paper presents a methodology for calculating the time-dependent reliability of a large system consisting of s-dependent components. A Markov-chain model is used and the numerical difficulties associated with large transition-probability matrices are reduced by a systematic ordering of the system states. A technique is also presented for the systematic merging of processes corresponding to systems exhibiting s 3mmetries.
Reliability optimization in telephone switching systems design. HENRY A. MALEC. IEEE Trans. Reliab. R-26, (3) 203 (August 1977). In the design of telephone switching systems, the sequence of reliability design functions can be stated as (1) the formation of reliability objectives, (2) the allocation of these objectives, and (3) the modeling to verify the reliability obtained. Optimization techniques can be used in both reliability allocation and reliability modeling. This paper discusses the formation of reliability objectives and the methods of reliability goal allocation. Modeling examples are presented of a component-level reliability vs cost tradeoff and a systemqevel reliability analysis. Optimum demonstration tests with grouped inspection data from an exponential distribution. WAYNE NELSON. IEEE Trans. Reliab. R-26, (3) 226 (August 1977). Life test data from periodic inspection of test items consist of the number
A cold standby redundant system with delayed switchover and preventive maintenance. V. S. SRIN1VASAN. IEEE Trans. Reliab. R-26, 13/ 238 (August 19771. This paper derives the s-expected time to failure of a 2-unit cold-standby redundant system with delayed switchover [I, 2] and with preventive maintenance/pm). A system consisting of two high power transmitters with an automatic switch composed of many electronic components is an example. A positive time delay T~ csee assumption 81 is used with a view to reduce the operating cost of a unit. The method of semi-Markov process is used to solve this problem [3].
World Abstracts on Microelectronics and Reliability
Parts, Hybrids, Packaging PHP-13, {3) 318 (Sept. 19771. Scanning electron microscopy was employed to characterize the structure of the soft-soldered .joints in Si power transistors (type 2N3055h which failed electrically during thermal cycling. Cracks were observed in the soldered joint of many failed devices. Crack propagation seems to be accelerated by the presence of voids in the joint region. The importance of the reactions between the Ni layers and Sn of the solder also affects the long-term reliability of the devices. Fractographs obtained from the failed devices reveal ductile flacture of the soft solder as well as creep or fatigue failure of the solder at the elevated temperature. Based on the structural studies of both failed and uncycled devices, some possibilities for improving device performance are discussed.
Drift of the breakdown voltage in p n junctions in silicon (walk-out). J. F. VERWEV, A. HERINGA. R. Dr WERDT and W. v. D. HOFSTAI). Solid-St. Electron. 20, 689 (1977). A quantitative model for the time behaviour of the walk-out phenomenon in planar p n junctions is given. The injection of hot carriers into SiO2 and subsequent trapping of part of them is assumed to be the origin of the walk-out. The model is found to be in reasonable agreement with the experimental results on both p + n and n ~ p junctions. The parameters in the model are discussed in relation with the experiments. Integrated circuit testing. MARK R. BARBER and ALFRED ZACHARtAS. Bell Labs Rec. p. 125 (May 1977). The process has been streamlined by computer simulation of integratedcircuit operation, simplified software and an efficient production-line setup.
EBIC--a valuable tool fiw semiconductor evaluation and failure analysis. JAMESR. BEALL. I 5th /t. Proc. Reliab Phys. IEEF,. Nevada. p. 61 11977). The Electron Beam Induced Current or EBIC mode of SEM operation is a powerfld tool for analyzing and evaluating semiconductor devices. The EBIC mode may surpass other SEM operating modes in value. EBIC provides the capability for measuring subsurthce electrical and physical parameters withottt mechanical damage to the surface. Semiconductor diffusions provide a unique quality m separating beam induced electron-hole carriers for imaging or measurement. The procedure is straightforward and utilizes a basic SEM having the capability for sample current imaging. For most applications it is not necessary to remove glass passivation or specially prepare the specimen surface. A familiarity with the mechanics of electron beam interactions with solid surfaces provides the basis for EBIC applications. Electrical degradation, due to electron beam irradiation damage, dictates that EBIC applications be limited to sample evaluation or failure analysis.
A system for an automatic detection of defects of semiconductor masks and printed circuit boards. ZmO'qEW M. \Vo.u Ik. E/c(t¢,,, le~hwd. 10, (4) 95 (1977).This paper presents a principle, an algorithm and a hardware system for an automatic detection of defects of PC boards and semiconductor masks. Results of the defect detection process are presented. Defects are detected independently of positions and rotations of examined objects. A dimensional control of particular regions on examined objects is possible. The systent does not treat an image edge uneveness in its digital representation as a defect. A hardware system may be a realtime operating one.
3. CIRCUIT AND SYSTEMS RELIABILITY, MAINTENANCE AND REDUNDANCY Design of self-checking and fault tolerant microprogrammed controllers. IAN WILLIAMSON. Radio Electron. Engr 47, (10) 449 (October 1977). A realization of a self-checking and fail-safe programmable controller which uses a new control memory organization to give a simPle and elegant implementation is described. Using this self-checking controller as an example, a new approach to fault-tolerant design referred to as Dual-Fail-Safe (DFS) is presented which utilizes two self-checking modules. The resulting fauR-tolerant system is shown to be less costly and significantly more reliable than a conventional Triple-Modular-Redundancy (TMR) system.
of items failing in each inspection period and are called grouped data. This paper presents statistical methods for reliability measurement and demonstration from grouped data on items from an exponential life distribution. The maximum likelihood method is used to estimate mean life; tables are given for optimum inspection times. A new statistical (demonstration) test for mean life is locally most powerful and is simpler than the test based on the maximum likelihood estimate. Tables for this test are provided. These tests also apply to a Weibull distribution with known shape parameter.
Combining diagnosis and emulation yields fast fault-finding. LAURENCE BADAGLIACCA and ROBERT CATTERTON. Electronics p. 107 (10 November 1977). Signature analysis and in-circuit emulation via microprocessor socket give test instrument powerful troubleshooting capabilities.
Markov processes for reliability analyses of large systems. IOANNIS A. PAPAZOGLOU and ELIAS P. GYFTOPOULOS. IEEE Trans. Reliab. R-26./3/232 (August 19771. This paper presents a methodology for calculating the time-dependent reliability of a large system consisting of s-dependent components. A Markov-chain model is used and the numerical difficulties associated with large transition-probability matrices are reduced by a systematic ordering of the system states. A technique is also presented for the systematic merging of processes corresponding to systems exhibiting s 3mmetries.
Reliability optimization in telephone switching systems design. HENRY A. MALEC. IEEE Trans. Reliab. R-26, (3) 203 (August 1977). In the design of telephone switching systems, the sequence of reliability design functions can be stated as (1) the formation of reliability objectives, (2) the allocation of these objectives, and (3) the modeling to verify the reliability obtained. Optimization techniques can be used in both reliability allocation and reliability modeling. This paper discusses the formation of reliability objectives and the methods of reliability goal allocation. Modeling examples are presented of a component-level reliability vs cost tradeoff and a systemqevel reliability analysis. Optimum demonstration tests with grouped inspection data from an exponential distribution. WAYNE NELSON. IEEE Trans. Reliab. R-26, (3) 226 (August 1977). Life test data from periodic inspection of test items consist of the number
A cold standby redundant system with delayed switchover and preventive maintenance. V. S. SRIN1VASAN. IEEE Trans. Reliab. R-26, 13/ 238 (August 19771. This paper derives the s-expected time to failure of a 2-unit cold-standby redundant system with delayed switchover [I, 2] and with preventive maintenance/pm). A system consisting of two high power transmitters with an automatic switch composed of many electronic components is an example. A positive time delay T~ csee assumption 81 is used with a view to reduce the operating cost of a unit. The method of semi-Markov process is used to solve this problem [3].