Maxwell SV Getting Started: A 2D Electrostatic Problem - LES

Getting Started: A 2D Electrostatic Problem
Set Up Materials
To define the material properties for the objects in the geometric model, you must:
• Assign the properties of a perfect conductor to both microstrips and the ground plane.
• Assign FR4-epoxy, a dielectric commonly used in circuit boards, to the substrate.
In general, to assign materials to objects:
1. If necessary, add materials with the properties of the objects in your model to the material database.
2. Assign a material to each object in the geometric model as follows:
a. Select the object(s) for which a specific material applies.
b. Select the appropriate material.
c. Click Assign to assign the selected material to the selected object(s).
In this sample problem, you do not have to add materials to the material database — all materials
that you will need are already included in the global material database that the simulator makes
available to every project.
Note You must assign a material to each object in the model.
Access the Material Manager
To access the Material Manager:
1. Click Setup Materials. A warning window appears, explaining that materials with a conductivity
greater than 10000 siemens per meter will be treated as perfect conductors and will be
excluded from the solution region. Materials with lower conductivities will be included in the
solution region; the conductivities of such materials will not effect the electrostatic simulation,
since no current flow is modeled.�
Note For highly conductive materials such as copper, the potential is the same across an object
that is assigned the material. Because of this, Maxwell 2D’s electrostatic field solver does
not generate a solution inside objects assigned these materials. Instead, it treats them as
though they were perfectly conducting.
5-2 Defining Materials and Boundaries