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Process variables in thick-film resistor fabrication
26
WORLD
ABSTRACTS
ON MICROELECTRONICS
All of the capacitors in this system show good insulation resistance. The capacitors have passed 1000 hr life tests at 85°C and 2 × 10 ~ V dc/cm. The 10 per cent glass-90 per cent ceramic capacitors showed aging of 3 per cent per decade of time. The 60, 50 and 40 per cent glass compositions show flat temperature coefficients, while the 10 per cent glass composition has a T C of --25 per cent to +10 per cent from --55 to +125°C.
Process variables in thick-film resistor fabrication. J. A. VAN HISE, Solid St. Technol. July (1970), p. 58. In the fabrication of thick-film resistors, the equipment, materials and environment all play significant roles in determining the overall distribution of as-fired resistor values. Knowledge of these various parameters and their interaction with each other can enable the manufacturer to optimize his thick-film process. The screen printers, the type of screen, the drying oven, and the firing furnace all contain variable which when understood can work to improve the process or at least define the process limits. The effects of environment such as humidity and temperature on equipment and material must be minimized to retain reasonable process control. The type of resistor and conductor paste used in combination with each other, how they interact and the degree of sensitivity that these materials have towards the other process variables determine the final distribution of as-fired resistors.
The effect of geometry on the characteristics of thick film resistors. D. E. RIEMER, Proc. 20th Electron. Compon. Conf., IEEE, 13-15 May (1970), p. 102. Presently available resistor inks are specified for sheet resistivity, temperature coefficient, noise, etc., hut little mention is made of the fact that all these parameters are a function of the resistor geometry.. The four edges of a printed resistor are sources of inhomogeneity that become more visible in their effect the smaller a resistor is in size. Test patterns can be used to evaluate the edge effect and to compare various inks. Emphasis of the geometry effect by the ink user will cause the ink manufacturer to develop inks that can be used for a wide range of resistor shapes and sizes without drastic distortion of resistor characteristics by the edge inhomogeneities.
Titanium nitride/titanium resistive glazes. C. Y. D. HUANG, Proc. 20th Electron. Compon. Conf., IEEE, 13-15 May (1970), p. 34. Resistive glazes based on T i n N / T i mixtures in a glass matrix have been studied. The variation of sheet resistance and temperature coefficient of resistance with changes in conductor concentration, firing temperature, ratio of ZinN/Ti, glass matrix and substrate composition are discussed. The flame-proof characteristic of this resistive glaze on over-load is discussed in detail.
AND RELIABILITY
palladium and silver has been introduced. It is primarily intended to provide stability in reactive, hostile environments. Processing is similar to that used for Pd-Ag resistors. The new system offers a wider resistance range of from 30-300 Kohms/square; a T C R of less than 100 ppm/°C; very low current noise and excellent load and no load storage stability. In addition, resistors from the "Birox" system are stable in forming gas at moderately elevated temperature. The use of a "preformed" conductive phase leads to higher substrate yeilds and combined with other properties allows "thick film" participation in markets formerly reserved for "thin film" resistor elements.
Custom design of thin-film hybrid circuits. K, HARRISON, Electron. Engng. June (1970), p. 63. In-house manufacture of thick- or thin-film circuits involves high capital outlay and the employment of suitably qualified personnel which, for all but the larger companies, makes it an impracticable proposition. In this article, the benefits of using the services of a company specializing in custom design are presented.
Wide band amplifier in thin film technique. H. WAGNER, Radio Mentor Electron. 36, No. 8, August (1970), p. 510, in German. The advantages of the application of thin film technique compared to the traditional design on an edged printed board can clearly be shown. The task consisted of developing a transistorized amplifier for a 50 ohm system which has a power gain of 20 dB with a maximum of ± 1 dB fluctuation over the frequency range 10 to 1000 MHz. Thus the following was achieved: (1) The emitter lead inductances become negligibly small (2) No frequency curve trimming is required. (3) The circuit is extremely well reproducible. (4) The number of soldered or bonded joint become essentially smaller. (5) The circuit becomes small and can therefore easily be incorporated in a high frequency compact casing. (6) Due to the small space required for the circuit, more precise high frequency measuring conditions can be obtained. (7) In addition to checking the basic functioning, no field test work is required after completion.
Recent developments in thin-film hybrid microcircuits. J. W. KANZ, Solid St. Technol. May (1970), p. 57. Thin-film hybrid microcircuit technology is rapidly maturing. While new materials and processing innovations continue to cause occasional excitement, more emphasis is now placed on the economics and applications of this approach. Even with competing technologies such as thick-film hybrids, the increasing scope of application, growing utilization, and steady technical progress in this field point to a vigorous future.
Prediction of the stability of thin-film resistors. J. C. ANDERSONand V. RYSANEK,Radio Electron. Engr.
Preliminary data for a n e w high performance 39, No. 6, June (1970), p. 321. A relationship is derived resistor series. L. C. HOFFMAN, K. E. SCHUBERT, between the contribution of defects to the resistivity of M. J. POPOWlCH and R. J. BOUCHARD,Solid St. Technol., a thin film and the non-linearity of its I - V characteristic. May (1970), p. 73. A new resistor system, free of
The latter is characterized by the "third-harmonic
WORLD
ABSTRACTS
ON MICROELECTRONICS
All of the capacitors in this system show good insulation resistance. The capacitors have passed 1000 hr life tests at 85°C and 2 × 10 ~ V dc/cm. The 10 per cent glass-90 per cent ceramic capacitors showed aging of 3 per cent per decade of time. The 60, 50 and 40 per cent glass compositions show flat temperature coefficients, while the 10 per cent glass composition has a T C of --25 per cent to +10 per cent from --55 to +125°C.
Process variables in thick-film resistor fabrication. J. A. VAN HISE, Solid St. Technol. July (1970), p. 58. In the fabrication of thick-film resistors, the equipment, materials and environment all play significant roles in determining the overall distribution of as-fired resistor values. Knowledge of these various parameters and their interaction with each other can enable the manufacturer to optimize his thick-film process. The screen printers, the type of screen, the drying oven, and the firing furnace all contain variable which when understood can work to improve the process or at least define the process limits. The effects of environment such as humidity and temperature on equipment and material must be minimized to retain reasonable process control. The type of resistor and conductor paste used in combination with each other, how they interact and the degree of sensitivity that these materials have towards the other process variables determine the final distribution of as-fired resistors.
The effect of geometry on the characteristics of thick film resistors. D. E. RIEMER, Proc. 20th Electron. Compon. Conf., IEEE, 13-15 May (1970), p. 102. Presently available resistor inks are specified for sheet resistivity, temperature coefficient, noise, etc., hut little mention is made of the fact that all these parameters are a function of the resistor geometry.. The four edges of a printed resistor are sources of inhomogeneity that become more visible in their effect the smaller a resistor is in size. Test patterns can be used to evaluate the edge effect and to compare various inks. Emphasis of the geometry effect by the ink user will cause the ink manufacturer to develop inks that can be used for a wide range of resistor shapes and sizes without drastic distortion of resistor characteristics by the edge inhomogeneities.
Titanium nitride/titanium resistive glazes. C. Y. D. HUANG, Proc. 20th Electron. Compon. Conf., IEEE, 13-15 May (1970), p. 34. Resistive glazes based on T i n N / T i mixtures in a glass matrix have been studied. The variation of sheet resistance and temperature coefficient of resistance with changes in conductor concentration, firing temperature, ratio of ZinN/Ti, glass matrix and substrate composition are discussed. The flame-proof characteristic of this resistive glaze on over-load is discussed in detail.
AND RELIABILITY
palladium and silver has been introduced. It is primarily intended to provide stability in reactive, hostile environments. Processing is similar to that used for Pd-Ag resistors. The new system offers a wider resistance range of from 30-300 Kohms/square; a T C R of less than 100 ppm/°C; very low current noise and excellent load and no load storage stability. In addition, resistors from the "Birox" system are stable in forming gas at moderately elevated temperature. The use of a "preformed" conductive phase leads to higher substrate yeilds and combined with other properties allows "thick film" participation in markets formerly reserved for "thin film" resistor elements.
Custom design of thin-film hybrid circuits. K, HARRISON, Electron. Engng. June (1970), p. 63. In-house manufacture of thick- or thin-film circuits involves high capital outlay and the employment of suitably qualified personnel which, for all but the larger companies, makes it an impracticable proposition. In this article, the benefits of using the services of a company specializing in custom design are presented.
Wide band amplifier in thin film technique. H. WAGNER, Radio Mentor Electron. 36, No. 8, August (1970), p. 510, in German. The advantages of the application of thin film technique compared to the traditional design on an edged printed board can clearly be shown. The task consisted of developing a transistorized amplifier for a 50 ohm system which has a power gain of 20 dB with a maximum of ± 1 dB fluctuation over the frequency range 10 to 1000 MHz. Thus the following was achieved: (1) The emitter lead inductances become negligibly small (2) No frequency curve trimming is required. (3) The circuit is extremely well reproducible. (4) The number of soldered or bonded joint become essentially smaller. (5) The circuit becomes small and can therefore easily be incorporated in a high frequency compact casing. (6) Due to the small space required for the circuit, more precise high frequency measuring conditions can be obtained. (7) In addition to checking the basic functioning, no field test work is required after completion.
Recent developments in thin-film hybrid microcircuits. J. W. KANZ, Solid St. Technol. May (1970), p. 57. Thin-film hybrid microcircuit technology is rapidly maturing. While new materials and processing innovations continue to cause occasional excitement, more emphasis is now placed on the economics and applications of this approach. Even with competing technologies such as thick-film hybrids, the increasing scope of application, growing utilization, and steady technical progress in this field point to a vigorous future.
Prediction of the stability of thin-film resistors. J. C. ANDERSONand V. RYSANEK,Radio Electron. Engr.
Preliminary data for a n e w high performance 39, No. 6, June (1970), p. 321. A relationship is derived resistor series. L. C. HOFFMAN, K. E. SCHUBERT, between the contribution of defects to the resistivity of M. J. POPOWlCH and R. J. BOUCHARD,Solid St. Technol., a thin film and the non-linearity of its I - V characteristic. May (1970), p. 73. A new resistor system, free of
The latter is characterized by the "third-harmonic