10X Faster Electromagnetic 3D Simulation

The importance of keeping your simulation software up to date.


Virtual prototypes are essential to optimize the signal integrity performance of their high-performance electronics products. Today, engineering teams are pushing to get fast electromagnetic (EM) simulations of printed circuit boards (PCB) and 3D chip packages in just a few hours with the highest level of accuracy.

The state of the art in EM simulation has come a long way: Back in 2000 it was viewed as a true breakthrough when, for the first time, an EM simulator – HFSS from Ansys – used a new matrix multiprocessing technology to simulate a differential pair interconnect with a full-wave 3D model.

Two decades later, in summer 2019, a key Ansys customer informed us that HFSS was taking an unacceptably long 28½ hours to simulate a 48-port PCB model. Investigation by customer support specialists revealed the customer was still using rules of thumb and approaches that were considered best practices in the early 2000s. They were making very narrow, conformal cutouts of power and ground layout structures for signal return paths which impacted boundary conditions for the simulation. There were also many small unconnected polygons created as artifacts by the cutout operation. This method is no longer appropriate or necessary with contemporary HFSS technology and, to make matters worse, the customer was using an old version of HFSS, four releases behind the latest technology. The disappointing run time for their PCB simulation was a result of the customer using an outdated and unnecessarily complex workflow and not using the latest HFSS advances they are entitled to.

Many of these outdated practices can be traced back to older versions of HFSS that had limitations in its meshing technology and restrictive rules needed to generate simplified 3D geometries on a just a single machine with limited RAM.

By using the latest HFSS version to automatically generate cutouts and remove floating polygons, the customer reduced their simulation runtime to just 2¾ hours. This is more than 10X faster than the original simulation time and was achieved by simply updating to the latest HFSS version and best practices.

Another recent example is a large semiconductor customer and longtime HFSS user who reported that HFSS was taking 61 hours to simulate a 40 port model. They had also found that another vendor’s simulator was able to solve a nearly identical model in only 9 hours.  Our discussion with the customer quickly identified that they were using an outdated methodology and an old version of HFSS with only 16 cores, while giving the other simulator 32 cores to work with. Within days, support engineers helped them upgrade to the latest HFSS version and shared best practices for creating HFSS models. We then re-simulated their model on identical resources – four machines with a total of 32 cores – and enabled HFSS’ distributed memory matrix (DMM) solver. This reduced HFSS runtime to just 5 hours, which is a 12x speed up and nearly twice as fast as the other simulator.

These are just two real-world examples reported by our customers that illustrate how Ansys HFSS technology is evolving and progressing with every new version. With the latest advancements in HFSS meshing technology, you can tackle much larger designs. And with HFSS’ DMM solver enabled, simulations run 10x faster, saving millions of dollars in product design expenses and weeks or months of product delay to market.

To give you an idea of where the true state-of-the-art in EM simulation is today, HFSS recently solved a full 3D model for a large PCB module with:

  • 8 two-layer flip-chip BGA packages
  • 64 signals
  • 128 ports
  • All plugged into a connector on a separate motherboard

This huge challenge was solved in only 34 hours by using HFSS DMM technology. Imagine what you could do with this advanced solver technology!

“The only constant in life is change,” said Heraclitus. We all face changes every day – whether a simple change in the weather, our schedule, a change of simulation methodologies or a new software version. Change affects us all and we each deal with change differently.

We must let go of the old rules of thumb, outdated methodologies and old software versions and utilize the latest advanced workflows and solutions. If you are looking for 10x faster solution with unmatched accuracy you probably already own it: the latest and greatest HFSS. The rising emphasis on simulation is driving all major customers to maximize their use of the latest EM capabilities in a familiar HFSS environment and assured of HFSS’ golden accuracy.

To see the latest HFSS version, contact your Ansys account team or visit our support line at support.ansys.com. For step-by-step video instructions on how to implement these best practices, check out the videos: Using HFSS to Optimize your Complex PCB Layout, True System Design with HFSS 3D Layout, and  Using Azure Cloud to Rapidly Simulate Layout Designs in HFSS.

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