Fast 3D Analysis of PCBs

Printed circuit board (PCB) designers grappling with signal integrity (SI) problems in high-speed digital systems can rely on HFSS Regions in ANSYS SIwave. This unique, automated simulation technology combines the best attributes of two electromagnetic field solvers — the gold-standard 3D accuracy of ANSYS HFSS and the remarkable speed and capacity of SIwave. It empowers designers to mitigate the SI challenges of high-speed electronic systems.

Watch HFSS Regions in SIwave in action. This short video demonstrates the extraction of PCIe gen 3 data channels on a large-data center server mother board and I/O board.

With this single solution, you can analyze 3D discontinuities with HFSS and long PCB transmission lines with SIwave to achieve superior S-parameter extraction accuracy for critical signal nets. This fast, memory-efficient domain-decomposition approach enables precise characterization of high-speed data channels. Moreover , the ability to distribute 3D structures like vias, bondwires, solder balls, etc., across compute resources and solve them in parallel dramatically accelerates the simulation process. These 3D structures on PCBs are defined as HFSS 3D regions in ANSYS SIwave. This feature is particularly beneficial if a large number of 3D regions are defined on a PCB. The parallel simulations expedite the 3D analyses of PCBs, leading to optimal and efficient use of the available HPC resources, as well as substantial reduction of simulation runtime.

           

Users need to only define 3D regions within their PCB layout; the rest of the simulation is automatic. The full-wave 3D analysis in HFSS occurs seamlessly with the 2.5D solution of SIwave. This results in the fast, efficient and accurate extraction of designated signal nets, coupled with the entire power delivery network in the design.

HFSS Regions in SIwave identifies and reduces PCB SI problems prior to fabrication. Less accurate extraction algorithms can cause engineers to misjudge the signal integrity of high-speed data channels.

The solution delivers:

  • Faster time to market for electronics.
  • Reduced costs.
  • Improved system performance.

This advanced simulation solution allows SI engineers to accurately predict and mitigate signal integrity issues in IC packages and PCBs, in applications ranging from consumer electronics, internet of things, automotive, aerospace to 5G-capable edge-compute data centers.

These data centers comprise fast channels (SERDES 25 – 100 Gbps and PAM4 56 Gbps and 112 Gbps), and are designed to rapidly process large amounts of data using high-speed signals. Because the channels must maintain signal quality for proper functioning and performance of the data centers, it is vital to characterize them and any associated 3D discontinuities (vias, solder balls, bumps, bond-wires) with higher accuracy.

Accurate S-parameter touchstone files automatically generated from HFSS Regions in SIwave simulations can be used in time-domain circuit simulations to obtain, among other metrics, TDR channel responses, signal net crosstalk and eye diagrams.

Additional Resources

For more details on this automated simulation technology, view the following resources.

server mother board

Figure 1. Server mother board 60 cm x 42 cm

 

 

PCB regions

Figure 2. Close-up of 3D regions