Guidelines for Using Dielectric Bricks
A dielectric brick simulates a volume of dielectric material. Because a brick simulates a volume, it must be subsectioned in the X, Y and Z dimensions. The more subsections (finer resolution) used in each dimension, the more accurate the analysis.
X/Y subsectioning of dielectric bricks is identical to X/Y subsectioning of metal polygons. You can control the X/Y subsectioning of both through your choice of grid size, XMIN, YMIN, XMAX, YMAX and subsections-per-wavelength. See Subsectioning for details.
Z subsectioning of dielectric bricks is controlled by the Brick Z-Partitions setting. This setting specifies the number of Z subsections for all dielectric bricks on a particular dielectric layer.
Vias through dielectric bricks are treated the same as vias through the standard dielectric layers. Note that via ports inside dielectric bricks are not allowed.
Dielectric bricks can be made of any dielectric material and can be placed in any circuit layer. This allows, for instance, “alumina” bricks to be created in an “air” circuit layer. However, it is also possible to reverse this scenario. Dielectric bricks made of “air” can also be created in alumina circuit layers. This is an important consideration to remember. Depending upon the circuit geometry for a given application, this ability to reverse the dielectric characteristics may simplify the circuit and make it faster to analyze.
In some cases, it is just as accurate to model a thin film capacitor by completely covering the entire work area with the capacitor dielectric. This is accurate when the capacitor dielectric is very thin and is within the same order of magnitude as the layers above and below it. Thus if you do not have a license for dielectric bricks, or if you need a faster analysis, you may want to consider this option. The example files brickcap and layercap contrast these two methods.