The Resistance Measurement buttons allow the user to measure the resistance between two points of the currently highlighted path.
Caveat: This is a new capability. The algorithm seems to have difficulty with some, usually complex, paths, meaning that a ``pivot too small'' or other error message will appear indicating lack of a solution.
All layers used in the path should have a sheet resistance specified. If no sheet resistance is specified, a value of 1 ohm/square is assumed. The sheet resistance can be specified directly with the Rsh keyword, or can be obtained if Rho or Sigma and Thickness have been given. If Rsh is not given, the value is taken as 1e6*Rho/Thickness, where Rho has units of ohm-meter and Thickness is given in microns. The conductivity Sigma is equal to 1.0/Rho. These keywords can be set in the technology file, or with the Tech Parameter Editor in the Attributes Menu.
To perform a measurement, the Define Terminals button should be used first to define two terminal locations. With the button pressed, drag mouse button 1 to define a rectangular area over some part of the displayed path. A box will be shown. Note that one must drag, with the mouse button pressed, to define the terminal area. Simply clicking has no effect. Repeat the process over another part of the displayed path, and a second box will be shown. These boxes represent the equipotential terminal areas assumed in the solver.
Once the terminals have been defined, pressing the Measure button should display the measured resistance on the prompt line. Diagnostic messages from the solver will be printed in the console window.
The algorithm does not include contact resistance between different metal layers.