Introduction

This section is composed of three parts: planar metalization loss, via metalization loss and dielectric layer loss. For information on dielectric brick loss, see Dielectric Bricks. Both the theoretical aspect of how Sonnet models loss and the practical how to of assigning loss in your circuit are covered, including the use of metal and dielectric material libraries.

There is also a paper available by the president and founder of Sonnet Software, Dr. James Rautio, which contains a detailed discussion of metal losses; see reference [15] in Sonnet References for a detailed description. This paper is also available on the Sonnet website.

There are two general metal types in Sonnet, planar metal types which are assigned to metal polygons, and via metal types which are assigned to via polygons. In metal polygons, the current flow is in the x and y direction, while in via polygons, the current flows in the z direction between metal levels. The underlying theory behind both types is the same, but the parameters you enter are based on the physical properties of the object for which you will use the metal. For example, a planar metal can be defined with a conductivity and a thickness, while a via metal can be defined with a conductivity and solid cross-sectional area. Planar metals are discussed first followed by via metals.