Mesh Fusion provides a single platform to predict EM interactions

Article By : Majeed Ahmad

Mesh Fusion provides a single platform for IC packages, PCBs, interposers, and any layered or laminated structure to predict EM interactions.

Meshing is really hard because it’s intrinsically tied to CAD, and CAD has limited tolerance. That, in turn, limits the design engineer’s ability to mesh a large geometric scale. So, while working on system-level designs such as antenna-on-platform, IC packages or any other complex electromagnetic (EM) system, engineers have to deal with a mix of different types of CADs. And they have to be extra careful about how they prepare the CAD and how they align different parts.

Ansys, which has developed different meshing technologies over the years, has introduced a solution that drives rapid and fully-coupled simulation of complex EM systems. HFSS Mesh Fusion combines ICs, packaging, PCBs, connectors, and antennas in a single high frequency structure simulator (HFSS) analysis tool to predict any EM interactions.

“When you have a large dynamic range in geometric scale, you want to simulate a PCB with an IC package alongside passive components on the IC,” said Matt Commens, lead product manager for HFSS at Ansys. “So, instead of simulating these parts separately, engineers can simulate them all together.”

thermal image of the Mesh Fusion signal integrity simulation of a multi-PCB systemFigure 1 Mesh Fusion can perform signal integrity simulation of a multi-PCB system, including connectors and flex cable. Source: Ansys

Commens added that before Mesh Fusion, it was one mesh fits all; “One of the hardest things in simulation is taking an arbitrary geometry and figuring out how to break it into multiple elements.” What Mesh Fusion brings to the table is the ability to mix and match all these meshing technologies locally and then apply different meshing technologies in parallel.

That’s how Mesh Fusion solves two fundamental challenges: handling of different types of geometries and geometric scales. So, when design engineers are meshing a connector, all they have to worry about is the connector’s dimensions. They don’t have to worry about super-small features on the PCB, and they can handle tolerance of small details while meshing the larger connector model.

Next, if engineers want to use that connector model later on in another simulation, they can grab that CAD, material properties, and defined ports and save it to a file they can use later on. Here, Mesh Fusion acts as a single checkbox with a very minimal change in flow for users.

program screenshot of a drone EM simulationFigure 2 High-frequency components such as antennas, RF, filters, and connectors in designs like drones will benefit from complex EM simulation systems. Source: Ansys

With a steady increase in high-frequency content, like 5G and mmWave ICs, devices are more likely to couple electromagnetically. Here, engineers simulating the IC and packaging separately can lead to issues like inductors coupling back to some of the traces in packaging. Therefore, instead of having two CADs or two geometric scales, Mesh Fusion provides a single platform for IC packages, PCBs, interposers, and any layered or laminated structure.

“If we know how the geometry is created, we can have an optimized approach for a more reliable mesh generation,” said Commens while summing up the HFSS Mesh Fusion technology. “Mesh Fusion is complex but straightforward.”

This article was originally published on EDN.

Majeed Ahmad, Editor-in-Chief of EDN, has covered the electronics design industry for more than two decades.

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