An Automatic , Precision 1 - MHz Digital LCR

This new LCR Meter is especially designed for measurements of low-value components in integrated circuits and thinJilm hybrid circuits, as wellas of discrete components. /t uses a four-pair measurement technique to reduce errors caused by stray capacitance, residual inductance, and mutual inductance of the tesf /eads. T N THE MANUFACTURE of integrated circuits, I good process control is essential if yield and reliability are to be maximized. Good process control requires many measurements of parameters on the chip; for example, capacitance versus voltage determines several electrical characteristics of junctions and is an important source of information about the process. Measurement of individual components is also important in the design, testing, and production of thin-film hybrid circuits. Components of interest include resistors, capacitors, inductors, diodes, and transistor junctions. Measurements of low-value components are, of course, subject to errors caused by parasitic reac-tances such as stray capacitance and residual in-ductance. To minimize these errors, the new HP Mo-deI427LA 7-MHz LCR Meter [Fig. r) uses a four-pair measurement technique: the interconnections between the instrument and the circuit under test are four coaxial cables up to one meter long. Also, offset adjustments are used to cancel stray capacitance and conductance or residual inductance and resistance in the test leads between the circuit under test and the inputs to the coaxial cables. The new LCR Meter typically makes five or more readings per second at basic accuracies of 0.1% in ca-pacitance measurements and O.2o/o in inductance, resistance, and conductance measurements. Its read-out is a four-digit light-emitting-diode display that has 90% overrange capability. It displays capaci-tance from 0,001 picofarad to 19.000 nanofarads, in-ductance from 0.1 nanohenry to 1900.0 microhen-ries, resistance from 0.001 ohm to 19.000 kilohms (or conductance from 0.01 micromhos to 190.00 milli-mhos), and dissipation factors of capacitors or induc-tors from 0.0001 to 1.6000. Because it is intended for semiconductor measurements , the test voltages and currents used by the new LCR Meter are low. Capacitance test voltages are 20 mV and 500 mV rms. Inductance test currents are 5 mA to 2 pA.A remotely programmable dc bias source provides 0 to 39.9 volts in 0.1V steps' Options are available for interfacing the LCR Meter to HP calculators and computers' Cover: Model 427 1 A Di gital LCB Meter is well suited for p rod u cti on measu re m e nts of chip capacitors and other components that are used on thinJilm hybrid …