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Active and passive components for attachment to thick film circuits
ABSTRACTS 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
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Processing ceramics to give suitable substrate characteristics. B. C. WATERFIELD,Radio Electron. Engr, October (1968), p. 244. The selection of the substrate material is dependent on the application for which the deposited circuit is intended. The normal production specifications for substrates are discussed and a brief description given of the production methods available. The reasons for the impurity ratio in the ceramic must be considered relevant to the type of deposition that will be applied and the degree of adherence that is required; there is also a connection between impurity level and surface finish which will affect the choice of metallizing media. In terms of both cost and surface texture, "as fired" ceramics are favoured. Any subsequent machining operations will tend to expose voids which can be clearly seen on roughness traces, though a general "flattening" of crystal peaks will take place. If a higher degree of surface finish is obligatory, then great care is needed in the selection of ceramic with particular reference to the size of grain and alumina content. Finally, the factors affecting the costs of production substrates are considered in light of the aspects discussed. Thick films headed for wide use in the 1970s. R. GECHMAN,Electron. Des. 16, 1 August (1968), p. 25. Diverse reasons are involved in the trend toward thick-film wafers. Uncased silicon-chip techniques are advancing. Such approaches as flip chips and LIDS (leadless inverted devices) are allowing the uncased chips to be connected to ceramic wafers. Beam leads, which will soon be available with a wide array of devices, promise further progress. Nitride passivation, which produces a hermetic seal without some of the problems associated with glass passivation, is another step forward. Within a year a number of manufacturers will be offering nitride-passivated beam-lead microcircuits. When used with uncased chips, thick film hybrids also offer high-temperature capability for direct chip-to-substrate bonding on to ceramic. A rigid structure-flexing would break bonds. Ability to make thin conductor stripes, yet retain bonding strength. Lower cost than alternative packaging approaches. Recent advances in thick film resistive materials. S. J. STEIN,Electron. Equip. News, July (1968), p. 24. Resistive glaze or Cermet coatings have been the subject of intensive investigation during the past few years. A number of different compositional systems have been reported including palladiumpalladium oxide-silver, indium oxide, thallium oxide, tungsten-tungstic carbide, and platinum-metalgroup combinations. A great deal of work has been performed in investigating new compositional variations, and in modifications of the above systems. Such studies have included addition of dopants, extenders, alloy formation, frit modifications, particle size and shape distributions, etc. Procedures involving variations in formulation of printing vehicles, blending, grinding, and mixing of pastes, screening properties, firing profiles, atmospheric effects, and protective coatings are all being studied in great depth. The importance of the modification and preparational factors can be as great as the choice of metal or semiconductor system. The performance of these glaze compositional systems is very good compared to older carbon-resin composition which have been in long-term use as discrete resistors. Glazes have advanced to levels which begin to challenge, and even outstrip, some performance characteristics of various thin films as well as certain wirewound resistors. Active and passive components for attachment to thick film circuits. A. F. DYSON and D. GROSVENOR, Radio Electron, Engr, January (1969), p. 25. This paper discusses the development of suitable passive components (resistors and capacitors) for use with thick film circuits. The techniques of attachment of these components to the circuits are described. Experience with the attachment of certain types of semiconductors to thick film circuits is also described.
A multi-layer thick film interconnection system. K. C. BINGHAMand Y. GURLER,Radio Electron. Engr, December (1968), p. 367. The paper describes a multi-layer interconnection system suitable for 50-100 unencapsulated integrated circuit elements of the type used in high-speed computers. The power and earth planes with their associate dielectrics are made using the thick film technique. Methods of producing the conductor and dielectric films are discussed. Two additional conductor planes, forming the signal matrix in which the logic connections are made, are deposited by the thin film technique.
155
Processing ceramics to give suitable substrate characteristics. B. C. WATERFIELD,Radio Electron. Engr, October (1968), p. 244. The selection of the substrate material is dependent on the application for which the deposited circuit is intended. The normal production specifications for substrates are discussed and a brief description given of the production methods available. The reasons for the impurity ratio in the ceramic must be considered relevant to the type of deposition that will be applied and the degree of adherence that is required; there is also a connection between impurity level and surface finish which will affect the choice of metallizing media. In terms of both cost and surface texture, "as fired" ceramics are favoured. Any subsequent machining operations will tend to expose voids which can be clearly seen on roughness traces, though a general "flattening" of crystal peaks will take place. If a higher degree of surface finish is obligatory, then great care is needed in the selection of ceramic with particular reference to the size of grain and alumina content. Finally, the factors affecting the costs of production substrates are considered in light of the aspects discussed. Thick films headed for wide use in the 1970s. R. GECHMAN,Electron. Des. 16, 1 August (1968), p. 25. Diverse reasons are involved in the trend toward thick-film wafers. Uncased silicon-chip techniques are advancing. Such approaches as flip chips and LIDS (leadless inverted devices) are allowing the uncased chips to be connected to ceramic wafers. Beam leads, which will soon be available with a wide array of devices, promise further progress. Nitride passivation, which produces a hermetic seal without some of the problems associated with glass passivation, is another step forward. Within a year a number of manufacturers will be offering nitride-passivated beam-lead microcircuits. When used with uncased chips, thick film hybrids also offer high-temperature capability for direct chip-to-substrate bonding on to ceramic. A rigid structure-flexing would break bonds. Ability to make thin conductor stripes, yet retain bonding strength. Lower cost than alternative packaging approaches. Recent advances in thick film resistive materials. S. J. STEIN,Electron. Equip. News, July (1968), p. 24. Resistive glaze or Cermet coatings have been the subject of intensive investigation during the past few years. A number of different compositional systems have been reported including palladiumpalladium oxide-silver, indium oxide, thallium oxide, tungsten-tungstic carbide, and platinum-metalgroup combinations. A great deal of work has been performed in investigating new compositional variations, and in modifications of the above systems. Such studies have included addition of dopants, extenders, alloy formation, frit modifications, particle size and shape distributions, etc. Procedures involving variations in formulation of printing vehicles, blending, grinding, and mixing of pastes, screening properties, firing profiles, atmospheric effects, and protective coatings are all being studied in great depth. The importance of the modification and preparational factors can be as great as the choice of metal or semiconductor system. The performance of these glaze compositional systems is very good compared to older carbon-resin composition which have been in long-term use as discrete resistors. Glazes have advanced to levels which begin to challenge, and even outstrip, some performance characteristics of various thin films as well as certain wirewound resistors. Active and passive components for attachment to thick film circuits. A. F. DYSON and D. GROSVENOR, Radio Electron, Engr, January (1969), p. 25. This paper discusses the development of suitable passive components (resistors and capacitors) for use with thick film circuits. The techniques of attachment of these components to the circuits are described. Experience with the attachment of certain types of semiconductors to thick film circuits is also described.
A multi-layer thick film interconnection system. K. C. BINGHAMand Y. GURLER,Radio Electron. Engr, December (1968), p. 367. The paper describes a multi-layer interconnection system suitable for 50-100 unencapsulated integrated circuit elements of the type used in high-speed computers. The power and earth planes with their associate dielectrics are made using the thick film technique. Methods of producing the conductor and dielectric films are discussed. Two additional conductor planes, forming the signal matrix in which the logic connections are made, are deposited by the thin film technique.