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New thick film functional devices
908
World Abstracts on Microelectronics and Reliability
bution to the manufacture of thick film circuits of low cost especially in view of recent large increases in the prices of precious metals.
Thick film circuits for telecommunications equipment. WILLIAM B. GRUPEN and HOWARD M. COHEN. Electrocompo~ent Sci. Teehnol. 8, 9 (1981). The use of thick film passive networks and hybrid integrated circuits by the Bell System is described in this paper. Included is a discussion of how attributes of thick films such as a large resistance range, high power handling capability, a bipolar capacitor and multilevel interconnection capability are used to provide a range of circuit properties that supplement the properties available in a well-established thin film technology. Design aids permitting a rapid transition from an electrical schematic to a finished circuit, special laser trimming procedures and material blending procedures are described for resistor networks. Also included are assembly and packaging techniques suitable for high reliability and low cost manufacturing. Several hybrid integrated circuits which benefit from the use of thick films are described in terms of their particular electrical or structural requirements. Included is a family of power converter circuits illustrating the advantages of a modular approach to circuit design in which functional resistor trimming provides a number of different circuit characteristics. Several applications involving the use of thick films in combination with thin films to provide special hybrid circuit properties not available from thin films alone are described. These and other possible uses of the two technologies in the same circuit are discussed in terms of combining the best properties of each technology to provide higher reliability and lower circuit cost. Finally, the future for the use of thick films in the Bell System is discussed. Thin film technology used in Bell System telecommunication circuits. WALTER WOROBEY. EleetrocomponelTt Sci. Technol. 8, 3 (1981). This paper describes the thin film technology used for telecommunication circuits in the Bell System. Vacuum deposition and photolithograpby form the basis for the film processing steps. Nitrogen doped tantalum films are used to form the very stable thin film resistors and capacitors. Laser trimming is used to obtain precision RC active filters. Line widths down to 751tm for conductors and 50,~lm for resistors are readily achieved in production. The properties of the various components used in thin film integrated circuits are described and examples of completed circuits used in transmission, station, and switching systems are shown. Some key advantages of this technology are low cost due to batch processing techniques, high packing density and high precision of passive components. Fabrication of nonreciprocal microwave components using thick film ferrimagnetie pastes. CHINMAV K. MAITL D. BHATTACHARYYA and N. B. CHAKRABARTL Electrocomponent Sci. Technol. 8, 111 (1981), This paper reports results of investigations on edge guided mode circulators and junction circulators using thick film ferrimagnetic pastes in the frequency range from 2 to 12 GHz, Performance of the circulators realized with the thick film fcrrimagnetic pastes will be compared with those made on YIG substrates in respect of insertion loss, isolation and bandwidth. The study shows that while good isolation bandwidth is obtainable with edge guided mode circulators, tile insertion Joss remains high. Characterization of thick-film compositions on RCA porcelaincoated steel substrates. A. N. PRABHU, K. W. HANG, E. J. CONLON, T. T. HITCH and A. KUSENKO. RCA Review 42, 239 (June 1981). A thick-film ink system comprising copper conductor, base metal resistor, low K dielectric, and overglaze compositions has been formulated for producing thick-film patterns and passive components on the RCA porcelain coated steel substrates. The properties of the copper film,
such as conductivity, solderability, solder leach resistance, solder aged adhesion and wire bondability, are reported. Resistor properties such as TCR, noise, geometry dependence, and solder dip stability are described, as well as the resistance drifts of laser trimmed resistors after thermal storage, thermal shock, power loading, and exposure to humidity. The effects of overglazing on the resistor properties have been determined. Data are also presented on the properties of the cross-over dielectric films. Infrared firing of thick film compositious. J. L. RESUTEK and R. E. COTE. Solid-State TechJ~olo.qy 39 (Jtme 1981). Tile performance characteristics of various thick film compositions were investigated after processing in a production type infrared (IR) furnace (Fig. 1~. Comparison with controls fired in a conventional thick film furnace indicates that Du Pont conductor, resistor, and dielectric thick film compositions can be fired successfully with the IR process. Various thick film condt, ctor. resistor, and dielectric compositions were printed and dried on 96 ",~,alumina substrates and fired in an IR furnace at 875°C peak temperature with an overall 15-minute cycle. Results obtained in this profile were compared to those obtained with a conventional furnace at 850°C peak, 60-minute overall cycle. Electrical and functional properties were compared. The effect of ambient atmosphere conditions on day-to-day reproducibility was also investigated. In addition, the infrared absorption of tile different thick film compositions is reported. Low-value nickel resistors electroless-plated on "IMST" substrate for power hybrid ICs. N. MIURA, Y. FUURA and A. KAZA/VI[.Electrocompol~ent Sei. Zec'hnol. 8, 83 (1981). This paper describes a new resistor formation technique, characterized by the use of our unique hybrid IC substrate (IMST substrate) and the electroless nickel plating on it. The evaluation of various electroless nickel plating baths to deposit nickel alloy with a different composition for each is included. The resistor properties of the nickel film from a selected bath are shown. The plating conditions affecting the resistance are discussed. Finally, tile application to the built-in emitter resistors of the I MST audio power hybrid IC is presented. New thick film functional devices. Y. TAKETA, O. ABE and M. HARADOME.Electrocompollent Sci. Technol. 8, 77 (1981). The development of thick-filnl functional devices having oscillation, negative resistance, switching, memory and so on has been needed. New non-volatile memory devices manufactured of Nb2Os-based thick-film have now been created. The thickfilm devices have been prepared by using c o m m o n thick-film technology such as screen printing, drying and firing. The characteristics and the operation of the devices are as follows: When a dc voltage is applied to the devices, rapid resistance change, so called switching effect, occnrs. The devices have low resistance state. Even when the voltage is removed completely, the devices do not return to high resistance state and keep low resistance state. However, when alternating voltage is impressed upon the devices, the low resistance state goes to the high resistance state. The recovery time of the resistance state depends upon the frequency of applied ac voltage. The higher frequency voltage that is applied, the sooner the recovery time becomes. The threshold voltage exponentially increases with higher frequency of an applied ac voltage. In addition to the memory effect, tile Nb2Os-based thickfilm devices have a switching and oscillation characteristic.
The design, construction, and evaluation of a porcelainizedsteel-substrate hybrid-circuit module. D. P. DORSEY, R. S. FILSON and W. H. TSIEN. RCA Review 42, 298 (June 1981). This paper summarizes the procedures used to build a TV B + Regulator on a porcelainized-steel substrate. The module
World Abstracts on Microelectronics and Reliability
bution to the manufacture of thick film circuits of low cost especially in view of recent large increases in the prices of precious metals.
Thick film circuits for telecommunications equipment. WILLIAM B. GRUPEN and HOWARD M. COHEN. Electrocompo~ent Sci. Teehnol. 8, 9 (1981). The use of thick film passive networks and hybrid integrated circuits by the Bell System is described in this paper. Included is a discussion of how attributes of thick films such as a large resistance range, high power handling capability, a bipolar capacitor and multilevel interconnection capability are used to provide a range of circuit properties that supplement the properties available in a well-established thin film technology. Design aids permitting a rapid transition from an electrical schematic to a finished circuit, special laser trimming procedures and material blending procedures are described for resistor networks. Also included are assembly and packaging techniques suitable for high reliability and low cost manufacturing. Several hybrid integrated circuits which benefit from the use of thick films are described in terms of their particular electrical or structural requirements. Included is a family of power converter circuits illustrating the advantages of a modular approach to circuit design in which functional resistor trimming provides a number of different circuit characteristics. Several applications involving the use of thick films in combination with thin films to provide special hybrid circuit properties not available from thin films alone are described. These and other possible uses of the two technologies in the same circuit are discussed in terms of combining the best properties of each technology to provide higher reliability and lower circuit cost. Finally, the future for the use of thick films in the Bell System is discussed. Thin film technology used in Bell System telecommunication circuits. WALTER WOROBEY. EleetrocomponelTt Sci. Technol. 8, 3 (1981). This paper describes the thin film technology used for telecommunication circuits in the Bell System. Vacuum deposition and photolithograpby form the basis for the film processing steps. Nitrogen doped tantalum films are used to form the very stable thin film resistors and capacitors. Laser trimming is used to obtain precision RC active filters. Line widths down to 751tm for conductors and 50,~lm for resistors are readily achieved in production. The properties of the various components used in thin film integrated circuits are described and examples of completed circuits used in transmission, station, and switching systems are shown. Some key advantages of this technology are low cost due to batch processing techniques, high packing density and high precision of passive components. Fabrication of nonreciprocal microwave components using thick film ferrimagnetie pastes. CHINMAV K. MAITL D. BHATTACHARYYA and N. B. CHAKRABARTL Electrocomponent Sci. Technol. 8, 111 (1981), This paper reports results of investigations on edge guided mode circulators and junction circulators using thick film ferrimagnetic pastes in the frequency range from 2 to 12 GHz, Performance of the circulators realized with the thick film fcrrimagnetic pastes will be compared with those made on YIG substrates in respect of insertion loss, isolation and bandwidth. The study shows that while good isolation bandwidth is obtainable with edge guided mode circulators, tile insertion Joss remains high. Characterization of thick-film compositions on RCA porcelaincoated steel substrates. A. N. PRABHU, K. W. HANG, E. J. CONLON, T. T. HITCH and A. KUSENKO. RCA Review 42, 239 (June 1981). A thick-film ink system comprising copper conductor, base metal resistor, low K dielectric, and overglaze compositions has been formulated for producing thick-film patterns and passive components on the RCA porcelain coated steel substrates. The properties of the copper film,
such as conductivity, solderability, solder leach resistance, solder aged adhesion and wire bondability, are reported. Resistor properties such as TCR, noise, geometry dependence, and solder dip stability are described, as well as the resistance drifts of laser trimmed resistors after thermal storage, thermal shock, power loading, and exposure to humidity. The effects of overglazing on the resistor properties have been determined. Data are also presented on the properties of the cross-over dielectric films. Infrared firing of thick film compositious. J. L. RESUTEK and R. E. COTE. Solid-State TechJ~olo.qy 39 (Jtme 1981). Tile performance characteristics of various thick film compositions were investigated after processing in a production type infrared (IR) furnace (Fig. 1~. Comparison with controls fired in a conventional thick film furnace indicates that Du Pont conductor, resistor, and dielectric thick film compositions can be fired successfully with the IR process. Various thick film condt, ctor. resistor, and dielectric compositions were printed and dried on 96 ",~,alumina substrates and fired in an IR furnace at 875°C peak temperature with an overall 15-minute cycle. Results obtained in this profile were compared to those obtained with a conventional furnace at 850°C peak, 60-minute overall cycle. Electrical and functional properties were compared. The effect of ambient atmosphere conditions on day-to-day reproducibility was also investigated. In addition, the infrared absorption of tile different thick film compositions is reported. Low-value nickel resistors electroless-plated on "IMST" substrate for power hybrid ICs. N. MIURA, Y. FUURA and A. KAZA/VI[.Electrocompol~ent Sei. Zec'hnol. 8, 83 (1981). This paper describes a new resistor formation technique, characterized by the use of our unique hybrid IC substrate (IMST substrate) and the electroless nickel plating on it. The evaluation of various electroless nickel plating baths to deposit nickel alloy with a different composition for each is included. The resistor properties of the nickel film from a selected bath are shown. The plating conditions affecting the resistance are discussed. Finally, tile application to the built-in emitter resistors of the I MST audio power hybrid IC is presented. New thick film functional devices. Y. TAKETA, O. ABE and M. HARADOME.Electrocompollent Sci. Technol. 8, 77 (1981). The development of thick-filnl functional devices having oscillation, negative resistance, switching, memory and so on has been needed. New non-volatile memory devices manufactured of Nb2Os-based thick-film have now been created. The thickfilm devices have been prepared by using c o m m o n thick-film technology such as screen printing, drying and firing. The characteristics and the operation of the devices are as follows: When a dc voltage is applied to the devices, rapid resistance change, so called switching effect, occnrs. The devices have low resistance state. Even when the voltage is removed completely, the devices do not return to high resistance state and keep low resistance state. However, when alternating voltage is impressed upon the devices, the low resistance state goes to the high resistance state. The recovery time of the resistance state depends upon the frequency of applied ac voltage. The higher frequency voltage that is applied, the sooner the recovery time becomes. The threshold voltage exponentially increases with higher frequency of an applied ac voltage. In addition to the memory effect, tile Nb2Os-based thickfilm devices have a switching and oscillation characteristic.
The design, construction, and evaluation of a porcelainizedsteel-substrate hybrid-circuit module. D. P. DORSEY, R. S. FILSON and W. H. TSIEN. RCA Review 42, 298 (June 1981). This paper summarizes the procedures used to build a TV B + Regulator on a porcelainized-steel substrate. The module