EM Extraction and Finite Element Method (FEM) in Clarity 3D Solver

EM Extraction

The Electromagnetic (EM) Extraction is simply the parasitic model extraction of electrical interconnect structures for PCB and Packages that are later used in SI and PI applications. Models derived from EM extraction can be W-Element transmission line models, SPICE sub-circuit (RLGC) models and in many cases S-parameter models.

The EM Extraction tools can be 2D or 3D. When we speak about PCB and Package structures, the notable difference between them is about ground reference. 2D solvers require a ground reference in the cross section (i.e. ground plane above or below). 3D tools are used when there is no ground reference in the 2D cross section

All EM Extraction tools use Maxwell’s Equation to solve for the structure.  The Static / Quasi-static solvers are fast, but only solver part of the equation is taken. In general, they are used for frequencies below 1 GHz.  Next are the Hybrid solvers, which make few assumptions, but can provide fast and practical answers. The results are highly accurate for frequencies up to 5 GHz

Finally, the Full Wave Solvers do not take short cuts – they solve all of Maxwell’s Equations and there is no theoretical frequency limit

3D Full-Wave Finite Element Method (FEM) Electromagnetic solvers are the trusted approach for High Frequency interconnect extraction. They solve the Maxwell differential equations and use adaptive numerical techniques.

How does the FEM work?

The solver subdivides entire volume into many small tetrahedral elements. The numerical unknowns are related to electrical fields on edges and faces of the tetrahedral elements as shown below.

For instance, for a 0^th order tetrahedral element, the 6 unknowns are related to electrical fields along the six edges. Once the electrical fields on edges and faces of the tetrahedral elements are solved, electrical fields at any points inside an element can be calculated explicitly according to the basis functions.

Limitations of the legacy EM Solvers

Notable among the limitations is regarding the high Turnaround Time where the simulation takes weeks to simulate owing to CPU crunch or memory crunch on the machines. Along with this, the Capacity to simulate complex and large structures is a limitation where the extraction engine can’t simulate these large structures.

This is both at the initial meshing step or later in the adaptive meshing stages to perform meshing for complex geometries. To get highly accurate result, the engine must segment structure for run through, which might consume more resources and increase time.

The legacy solutions seemingly lacked integration with VRF and Allegro since they were not initially built with them in mind. Finally, Users want less resource footprint and want the Cloud adaptability, thereby rending the legacy solutions undeployable in Cloud environment

How does Clarity3D Solver addresses this?

• 10x faster than existing solution
• Capabilities to simulate large structures
• Capability to mesh complex geometries
• Powerful matrix solver to solve huge matrices
• Native integration with design platforms
• Even capable of using small memory footprint machines (32GB) on the cloud

• Cadence^® Clarity 3D Solver
• The first product in Cadence’s system analysis initiative, breakthrough EM simulation technology delivers up to 10X performance with virtually unlimited capacity and gold-standard accuracy
• Architecture allows solver to be run on hundreds of CPUs optimized for both cloud and on-premises distributed computing
• True 3D model extraction eliminates risk from manually reducing the size of structures being modeled
• Easily reads design data from all standard chip,
  IC package, and PCB platforms and offers unique integration with Cadence implementation platforms

Clarity 3D Solver offers unprecedented performance and capacity.  Click here  to get all the information