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MOS firms eye 1-transistor cells
20
WORLD
ABSTRACTS
ON MICROELECTRONICS
Thermal analysis of beam-lead transistor chip. K. KaNI, M.
KAMOSHIDA,K. SATO and T. OKADA.
NEC Res. Dev. Japan, No. 21, April (1971), p. 90. The program package which is applicable to solve problems of heat transfer in transistors or integrated-circuit chips or in their stems has been developed with a threedimensional lumped network model. The thermal resistances of beam-lead transistors are evaluated with this program for various geometries of the chip and the beam-lead, and for passivation films. The results calculated indicate that the thermal resistance is mainly dependent on the thickness of electroplated Au in the beam-lead structure, and are found to be in good agreement with the observed values. A l u m i n u m ultrasonic joining in spider and wire connections. E. PHILOFSKY, R. BOWMAN and W. MILLEa, Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 289. Aluminum ultrasonic joining has become a major process for achieving interconnections in semiconductor devices today. The all-aluminum system is the most economical system which satisfies all the general requirements for interconnections (conductivity, ohmic contact to silicon, adhesion to glass, bondability). The ultrasonic joining process has proven to be the most rapid and reliable for bonding aluminum. In this paper the metallurgy of aluminum ultrasonic joining is discussed. A survey of the current state of the art of aluminum ultrasonic wire bonding is presented, and many of the details of the new aluminum ultrasonic spider bonding process are discussed.
Coming up fast f r o m behlnd--denser bipolar devices. J. A. DEFALCO. Electronics, 19 July (1971), p. 76. Because it is now possible to diffuse very thin epitaxial layers, and because new methods of isolating transistors have been developed, bipolar ICs today can achieve NIOS component densities. A plasma oxidation process for r e m o v i n g photoresist films. S. M. IRVING. Solid State Technol., June (1971), p. 47. The plasma oxidation process employs a low pressure, electrodelessly generated, low temperature oxygen plasma to react the photoresist into its volatile components. Processing variables, such as photoresist type, handling procedures, substrate variations and the effect of the plasma on various device types are discussed. A flow chart for the optimum use of the method is described.
Photoformed plated interconnection of e m b e d d e d IC chips. E. A. GUDITZ and R. L. BURKE. Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 137. A process is described for prototyping arrays of integrated-circuit chips in which the chips are embedded face-up in plastic and interconnected with photoformed plated conductors. Insulation layers consist of selectively-crosslinked polyester resin. Heat is removed to a sink through thermal paths from the bottom of the chips. The equipment required is relatively simple and inexpensive and turn-aroundtime is short. Given the required chips and masks, an array can be assembled in a few hours.
6. M I C R O E L E C T R O N I C S - - C O M P O N E N T S ,
The effect of the physical properties of a l u m i n a substrates on their use in m i c r o w a v e hybrid circuits. J. R. BOSNELL. Microelectronics 3, No. 10 (1971), p. 33. Results are presented on the dielectric constant and loss tangent at 10 GHz of alumina substrates as a function of composition and density. It is shown that density is the most important parameter in determining these properties. The effect of surface finish upon total loss in microstrip circuits fabricated from such substrates was found to be small for a surface finish of less than 10 ~in. centre line average (CLA). Plated-up, vacuum deposited conductors are compared with screenprinted conductors in microstrip circuits on such substrates and it is observed that the Q of circuits made by the latter technique is half of those made by the former.
Semiconductor random-access m e m o r i e s . L. L. VADASZ, H. T. CHUA and A. S. GROVE. IEEE Spectrum, May (1971), p. 40. In the last few years, semiconductor random-access memory (RAM) components have been introduced into high-speed scratchpad applications and small buffer memory systems, where the performance or cost advantage of semiconductor components is greatest. More recently, developments in the technology of largescale integrated (LSI) circuits have resulted in cost-
AND RELIABILITY
SYSTEMS AND EQUIPMENTS
performance characteristics of semiconductor RAMs that are competitive in computer main-frame memories as well. This article reviews the basic circuit concepts used in these components, representative products that are presently available, and some systems considerations involved in their use.
MOS firms eye 1-transistor cells. A. ROSENBLATT. Electronics, 30 August (1971), p. 67. Advocates of fast, dense memory design say it has the edge for upcoming 4, 096-bit RAMs; 3-transistor stalwarts doubt its performance capabilities.
Designing differential FET inputs with overall performance in m i n d . L. DIAMOND and A. V. SIEFERT. Electronics, 21 June (1971), p. 76. Inherent advantages of using F E T inputs in an operational amplifier will be diminished unless the designer also considers thermal stability as well as sensitivity, noise and commonmode characteristics.
A 20 M H z digital frequency m e t e r using tfl integrated circuits (Part 1). I. D. BROWN and S. L. NORMAN. Radio Commun., July (1971), p. 458. A digital frequency meter was a logical extension to the integrated
WORLD
ABSTRACTS
ON MICROELECTRONICS
Thermal analysis of beam-lead transistor chip. K. KaNI, M.
KAMOSHIDA,K. SATO and T. OKADA.
NEC Res. Dev. Japan, No. 21, April (1971), p. 90. The program package which is applicable to solve problems of heat transfer in transistors or integrated-circuit chips or in their stems has been developed with a threedimensional lumped network model. The thermal resistances of beam-lead transistors are evaluated with this program for various geometries of the chip and the beam-lead, and for passivation films. The results calculated indicate that the thermal resistance is mainly dependent on the thickness of electroplated Au in the beam-lead structure, and are found to be in good agreement with the observed values. A l u m i n u m ultrasonic joining in spider and wire connections. E. PHILOFSKY, R. BOWMAN and W. MILLEa, Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 289. Aluminum ultrasonic joining has become a major process for achieving interconnections in semiconductor devices today. The all-aluminum system is the most economical system which satisfies all the general requirements for interconnections (conductivity, ohmic contact to silicon, adhesion to glass, bondability). The ultrasonic joining process has proven to be the most rapid and reliable for bonding aluminum. In this paper the metallurgy of aluminum ultrasonic joining is discussed. A survey of the current state of the art of aluminum ultrasonic wire bonding is presented, and many of the details of the new aluminum ultrasonic spider bonding process are discussed.
Coming up fast f r o m behlnd--denser bipolar devices. J. A. DEFALCO. Electronics, 19 July (1971), p. 76. Because it is now possible to diffuse very thin epitaxial layers, and because new methods of isolating transistors have been developed, bipolar ICs today can achieve NIOS component densities. A plasma oxidation process for r e m o v i n g photoresist films. S. M. IRVING. Solid State Technol., June (1971), p. 47. The plasma oxidation process employs a low pressure, electrodelessly generated, low temperature oxygen plasma to react the photoresist into its volatile components. Processing variables, such as photoresist type, handling procedures, substrate variations and the effect of the plasma on various device types are discussed. A flow chart for the optimum use of the method is described.
Photoformed plated interconnection of e m b e d d e d IC chips. E. A. GUDITZ and R. L. BURKE. Proc. 21st Electronic Components Conf., Washington DC, USA, 10-12 May (1971), p. 137. A process is described for prototyping arrays of integrated-circuit chips in which the chips are embedded face-up in plastic and interconnected with photoformed plated conductors. Insulation layers consist of selectively-crosslinked polyester resin. Heat is removed to a sink through thermal paths from the bottom of the chips. The equipment required is relatively simple and inexpensive and turn-aroundtime is short. Given the required chips and masks, an array can be assembled in a few hours.
6. M I C R O E L E C T R O N I C S - - C O M P O N E N T S ,
The effect of the physical properties of a l u m i n a substrates on their use in m i c r o w a v e hybrid circuits. J. R. BOSNELL. Microelectronics 3, No. 10 (1971), p. 33. Results are presented on the dielectric constant and loss tangent at 10 GHz of alumina substrates as a function of composition and density. It is shown that density is the most important parameter in determining these properties. The effect of surface finish upon total loss in microstrip circuits fabricated from such substrates was found to be small for a surface finish of less than 10 ~in. centre line average (CLA). Plated-up, vacuum deposited conductors are compared with screenprinted conductors in microstrip circuits on such substrates and it is observed that the Q of circuits made by the latter technique is half of those made by the former.
Semiconductor random-access m e m o r i e s . L. L. VADASZ, H. T. CHUA and A. S. GROVE. IEEE Spectrum, May (1971), p. 40. In the last few years, semiconductor random-access memory (RAM) components have been introduced into high-speed scratchpad applications and small buffer memory systems, where the performance or cost advantage of semiconductor components is greatest. More recently, developments in the technology of largescale integrated (LSI) circuits have resulted in cost-
AND RELIABILITY
SYSTEMS AND EQUIPMENTS
performance characteristics of semiconductor RAMs that are competitive in computer main-frame memories as well. This article reviews the basic circuit concepts used in these components, representative products that are presently available, and some systems considerations involved in their use.
MOS firms eye 1-transistor cells. A. ROSENBLATT. Electronics, 30 August (1971), p. 67. Advocates of fast, dense memory design say it has the edge for upcoming 4, 096-bit RAMs; 3-transistor stalwarts doubt its performance capabilities.
Designing differential FET inputs with overall performance in m i n d . L. DIAMOND and A. V. SIEFERT. Electronics, 21 June (1971), p. 76. Inherent advantages of using F E T inputs in an operational amplifier will be diminished unless the designer also considers thermal stability as well as sensitivity, noise and commonmode characteristics.
A 20 M H z digital frequency m e t e r using tfl integrated circuits (Part 1). I. D. BROWN and S. L. NORMAN. Radio Commun., July (1971), p. 458. A digital frequency meter was a logical extension to the integrated