ABSTRACT
The assembly of semiconductor and hybrid integrated circuits for microwave and millimeter-wave frequencies generally requires the use of gold bondwires, ribbons, or mesh. The impedance of the interconnection must be accounted for in a good design. Unfortunately, there is no single accepted electrical model. The complexity required of the model will depend on the frequency of operation and the general impedance levels of the circuits being connected. At low frequencies and moderate to high impedances, the connection is frequently modeled as an inductor (sometimes in series with a resistor); at high frequencies, a full 3-D electromagnetic simulation may be required for accurate results. At intermediate points it may be modeled as a high impedance transmission line or as a lumped LC circuit. Note that the resistances of the rf interconnects should be included in the design of extremely low-noise circuits as they will affect the noise figure. In connecting a semiconductor die to package leads, it may also be necessary to model
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the mutual inductances and interlead capacitances in addition to the usual self inductances and shunt capacitance. Figure 13 illustrates one method of modeling bond wire inductance that has been shown adequate for many microwave applications. More sophisticated methods of modeling bond wires, ribbon or mesh are described in the references.
