- Email: [email protected]
Cleaners and cleaning for components and microelectronics
WORLD
ABSTRACTS
ON MICROELECTRONICS
provides acceptable operation in the presence of failures, but the redundant elements themsclves cause additional modes. This, plus the fact that component failures reduce the available dynamic range of the R A M P (which may also be classified as a failure), makes the decision of when to use the RAMP configuration a difficult one. It cannot be based on a surface inspection or intuition.
Comparison of predicted microwave radio outages. J. L. WILLIAMS, Telecommunications, August (1970), p. 19. This paper describes the results of a detailed
AND RELIABILITY
123
study, performed with the aid of computer techniques, to determine the variations of the reliability figure-ofmerit, "availability", for different line-of-sight microwave radio systems as the per-hop path length of such systems was varied. Predicted failure rates derived in accordance with M I L - H A N D B O O K - 2 1 7 A were used for the equipment bases; propagation outages were based upon latest available equations derived from empirical data. Computations and comparisons are applicable to operation at 6.6 GHz in three different types of weather and terrain conditions commonly encountered within the continental United States.
4. M I C R O E L E C T R O N I C S - - G E N E R A L
Cleaners and cleaning for components and microelectronics. H. H. MANKO, Proc. 1970 20th Electronic Components Conf., Washington, 13-15 May (1970), p. 129. T h e biggest problem encountered in cleaning electronic hardware originates from the lack of associating "invisible dirt" with malfunction of electronic systems. Harmful deposits not visible to the naked eye often, by their mere presence, cause erratic behavior of the circuitry by interfering with the insulating and conducting components. In our profit-oriented industry, only a true value analysis can prove the need for cleaning and justify the extra cost which, in many cases, is returned manifold through improved quality, reduction of rejections, and, often costly repair and corrosion. The selection of the right cleaning media is a scientific problem that needs careful analysis to ensure the removal of both polar and non-polar contaminants, without damage to the assembly. Many of the solvents prevalent on the market were never designed nor intended for the electronics industry and, as a result, can cause damage rather than rectify it. Levels of cleaners for specific equipment depend on many parameters. The factors outlined in this paper should make it simple to determine what is applicable for specific equipment.
Technological advances in large-scale integration. H. T. HOCHMAN and D. L. HOGAN, IEEE Spectrum, May (1970), p. 50. Large-scale integration is now coming of age, and within a short time its impact on the semiconductor industry is expected to be dramatic and far-reaching.
An educational thick film microcircuitry facility. P. G. BARNWELL,Int. 7. elect. Engng. Educ. 8 (1970), p. 429. T h e growth of mieroclectronics in recent years has placed educational establishments at some disadvantage, due to the high capital cost of equipment for work 5. M I C R O E L E C T R O N I C S
in this field. Facilities for the manufacture of monolithic circuits are only available at one or two universities in the United Kingdom, notably at the Universities of Southampton and Edinburgh. However, hybrid microcircuits are not so demanding in terms of equipment and accuracy of work, nor do they require clean rooms for their fabrication. In particular, thick film circuits have been shown to possess many advantages and are finding an increasing number of applications. It was felt that the establishment of such a facility at Brighton College of Technology would be of use for both research work and advanced undergraduate work. T h e cost of setting up even this type of facility involves considerable expenditure, if commercial equipment is purchased. By means of purchasing some commercial equipment and manufacturing the remainder in the department, a considerable saving has been effected and at the same time, a number of interesting projects for students have been presented in the design of certain parts of the system.
Integrated circuits for the industrial w o r l d . L. MAUL, Solid State Technology, September (1970), p. 43. Digital integrated circuits and electronic computers have been almost inseparably linked for years. A variety of logic families has been devcloped to meet the needs of computer and related applications. Recently, however, a significant role for logic circuits has emerged outside of the computer field--in fact, outside of the traditional electronics industry. This new field is industrial control. Various circuits of this nature are described in this article. The latest word in leak detection. I. LITANT, EDN, 15 October (1970), p. 35. Simple and reliable detection of leaks in hermetically sealed devices is made possible by a new fluorinated liquid and a halogen leak detector. The new method overcomes most of the shortcomings of standard leak-test procedures.
DESIGN AND CONSTRUCTION
Selection parameters for hybrid b o n d i n g alloys. A. R. I~OEHS, Proc. 1970 20th Electronic Components Conf., Washington, 13-15 May (1970), p. 116. T h e use of bonding alloys has been accepted as a desirable
method for the attachment of active components, passive components and leads to metalized hybrid circuit substrates for many reasons, including ease of hybrid device fabrication and simplicity of repairability.
ABSTRACTS
ON MICROELECTRONICS
provides acceptable operation in the presence of failures, but the redundant elements themsclves cause additional modes. This, plus the fact that component failures reduce the available dynamic range of the R A M P (which may also be classified as a failure), makes the decision of when to use the RAMP configuration a difficult one. It cannot be based on a surface inspection or intuition.
Comparison of predicted microwave radio outages. J. L. WILLIAMS, Telecommunications, August (1970), p. 19. This paper describes the results of a detailed
AND RELIABILITY
123
study, performed with the aid of computer techniques, to determine the variations of the reliability figure-ofmerit, "availability", for different line-of-sight microwave radio systems as the per-hop path length of such systems was varied. Predicted failure rates derived in accordance with M I L - H A N D B O O K - 2 1 7 A were used for the equipment bases; propagation outages were based upon latest available equations derived from empirical data. Computations and comparisons are applicable to operation at 6.6 GHz in three different types of weather and terrain conditions commonly encountered within the continental United States.
4. M I C R O E L E C T R O N I C S - - G E N E R A L
Cleaners and cleaning for components and microelectronics. H. H. MANKO, Proc. 1970 20th Electronic Components Conf., Washington, 13-15 May (1970), p. 129. T h e biggest problem encountered in cleaning electronic hardware originates from the lack of associating "invisible dirt" with malfunction of electronic systems. Harmful deposits not visible to the naked eye often, by their mere presence, cause erratic behavior of the circuitry by interfering with the insulating and conducting components. In our profit-oriented industry, only a true value analysis can prove the need for cleaning and justify the extra cost which, in many cases, is returned manifold through improved quality, reduction of rejections, and, often costly repair and corrosion. The selection of the right cleaning media is a scientific problem that needs careful analysis to ensure the removal of both polar and non-polar contaminants, without damage to the assembly. Many of the solvents prevalent on the market were never designed nor intended for the electronics industry and, as a result, can cause damage rather than rectify it. Levels of cleaners for specific equipment depend on many parameters. The factors outlined in this paper should make it simple to determine what is applicable for specific equipment.
Technological advances in large-scale integration. H. T. HOCHMAN and D. L. HOGAN, IEEE Spectrum, May (1970), p. 50. Large-scale integration is now coming of age, and within a short time its impact on the semiconductor industry is expected to be dramatic and far-reaching.
An educational thick film microcircuitry facility. P. G. BARNWELL,Int. 7. elect. Engng. Educ. 8 (1970), p. 429. T h e growth of mieroclectronics in recent years has placed educational establishments at some disadvantage, due to the high capital cost of equipment for work 5. M I C R O E L E C T R O N I C S
in this field. Facilities for the manufacture of monolithic circuits are only available at one or two universities in the United Kingdom, notably at the Universities of Southampton and Edinburgh. However, hybrid microcircuits are not so demanding in terms of equipment and accuracy of work, nor do they require clean rooms for their fabrication. In particular, thick film circuits have been shown to possess many advantages and are finding an increasing number of applications. It was felt that the establishment of such a facility at Brighton College of Technology would be of use for both research work and advanced undergraduate work. T h e cost of setting up even this type of facility involves considerable expenditure, if commercial equipment is purchased. By means of purchasing some commercial equipment and manufacturing the remainder in the department, a considerable saving has been effected and at the same time, a number of interesting projects for students have been presented in the design of certain parts of the system.
Integrated circuits for the industrial w o r l d . L. MAUL, Solid State Technology, September (1970), p. 43. Digital integrated circuits and electronic computers have been almost inseparably linked for years. A variety of logic families has been devcloped to meet the needs of computer and related applications. Recently, however, a significant role for logic circuits has emerged outside of the computer field--in fact, outside of the traditional electronics industry. This new field is industrial control. Various circuits of this nature are described in this article. The latest word in leak detection. I. LITANT, EDN, 15 October (1970), p. 35. Simple and reliable detection of leaks in hermetically sealed devices is made possible by a new fluorinated liquid and a halogen leak detector. The new method overcomes most of the shortcomings of standard leak-test procedures.
DESIGN AND CONSTRUCTION
Selection parameters for hybrid b o n d i n g alloys. A. R. I~OEHS, Proc. 1970 20th Electronic Components Conf., Washington, 13-15 May (1970), p. 116. T h e use of bonding alloys has been accepted as a desirable
method for the attachment of active components, passive components and leads to metalized hybrid circuit substrates for many reasons, including ease of hybrid device fabrication and simplicity of repairability.