Ansys SIwave Solvers

SIwave enables a streamlined ECAD design flow for 3-D electromagnetics, 2.5-D electromagnetics, 3-D thermal and circuit solvers. From the SIwave environment, you can invoke the precise solver technology for the analysis at hand. The solvers are listed here:

DCIR

The DCIR solver specializes in predicting DC power delivery issues within electronic packages and PCBs. The solver uses a unique adaptive mesh refinement algorithm to ensure highly accurate modeling of ECAD primitives such as planes, traces, vias, bondwires, solder balls and solder bumps. The DC solver also allows bi-directional coupling with Ansys Icepak to account for thermal effects due to Joule heating.

AC Solver

The Ansys SIwave AC solver computes resonant modes, SYZ parameters and frequency domain voltages. It also predicts near and far field radiated emissions. Incorporating sophisticated domain decomposition techniques, the AC solver is well suited for modeling non-ideal structures in the largest, most complex designs. Such structures include (but are not limited to) traces routed across splits, poorly referenced traces and vias contained within irregular antipads. The AC solver also incorporates rapid, full-design signal net scan capabilities, allowing SI engineers to quickly identify trace impedance and time/frequency-domain crosstalk violations.

PSI

The PSI 3-D Fast FEM solver is used for extracting PDN S-parameter or SPICE models from IC packages and PCBs. In addition, 3D AC currents can be visualized in SIwave showing signal, power and return currents.

CPA

The chip-package analysis (CPA) solver is used for extracting RLGC netlists for large chip-package designs. IC designers leverage the CPA solver within Ansys RedHawk for co-visualization of chip and package designs.

Q3D Extractor

The Q3D solver is used for performing high-accuracy RLC parasitic extractions on IC packages and PCBs.

Optional solvers integrated into SIwave are as follows:

HFSS

The HFSS 3D FEM solver can be used for extracting S-parameter or SPICE models from IC packages and PCBs.

Icepak

The Icepak solver can be used for thermal analysis of an IC package or PCB. An automated, iterative convergence solution between SIwave-DC and Icepak provides bi-directional electronics cooling solutions for IC packages and PCBs.

Nexxim

The Nexxim circuit solver can be used when time domain SPICE analysis is required for timing analysis.

HSPICE

The HSPICE circuit solver can be used from the SIwave desktop when time-domain SPICE analysis is required for timing analysis.

Layout and Geometry Import

SIwave seamlessly integrates into existing EDA design flows by importing ECAD geometry, materials and components directly from third-party EDA layout tools directly or using the ODB++ standard. Supported ECAD translations are listed in the table below.

Supported ECAD Translations

Electrothermal and Mechanical Analysis

SIwave links to the Ansys software portfolio for multiphysics simulation of electronic components. One option is to export a power distribution map from SIwave into Ansys Icepak. This multiphysics solution enables accurate thermal modeling of IC packages and PCBs using DC power loss from SIwave as a heat source. Icepak solves the challenges associated with dissipation of thermal energy from electronic components that may cause premature component failure due to overheating. You can then evaluate thermal stress with Ansys Mechanical. This multiphysics approach enables you to perform coupled EM–thermal–stress analysis for a complete understanding of the design prior to manufacturing.

High-Performance Computing

Adding an Ansys Electronics HPC license to SIwave opens a world of bigger, faster and higher-fidelity simulations. Ansys goes well beyond simple hardware acceleration to deliver groundbreaking numerical solvers and HPC methodologies optimized for single multicore machines and scalable to take advantage of full cluster power.

Multithreading
Take advantage of multiple cores on a single computer to reduce solution time. Multithreading technology speeds up the initial mesh generation, direct and iterative matrix solves, and field recovery.

Spectral Decomposition Method
The majority of electromagnetic simulations require results such as near field, far field and s-parameter data over a range of frequencies. Spectral decomposition distributes the multiple frequency solution in parallel over compute cores to accelerate frequency sweeps. You can use this method in tandem with multithreading. Multithreading speeds up extraction of each frequency point, while spectral decomposition performs many frequency points in parallel. The spectral decomposition method is scalable to large numbers of cores, offering significant computational acceleration.

IBIS and IBIS-AMI SerDes Analysis

Ansys SIwave includes circuit solutions for both parallel and SerDes busses. This includes simulation with the IBIS and IBIS-AMI driver/receiver models using the Ansys Nexxim or HSPICE circuit solver engine, as well as IBIS and IBIS-AMI model generation with our new SPISim technology. Full schematic capture and parametric design for design of experiments (DoE) is included.

Virtual Compliance

SIwave enables you to determine if your DDR3/4 busses pass or fail the Jedec standard. This solution provides pass/fail criteria for key timing metrics, such as data setup and hold timings, derated analyses, bit-to-bit skew timing, overshoot, undershoot, etc. The programming environment enables customization of compliance reporting for almost any standard: DDR, USB, PCIe, MIPI, CISPR EMC, etc. Additionally, our new SPISim technology allows for simple compliance reporting for USB-C and COM calculations for IEEE 802.3bj and 802.3bs channels.

Automated Decoupling Capacitor Optimization

When working in deep submicron technologies, you have the task of reducing design costs to meet tight schedules on-budget. Optimization of today's high-volume PCBs and packages is mostly based on different capacitor models, capacitor prices and numbers of capacitors, and it must be achieved without compromising the design's signal- and power-integrity performance. SIwave-PI can find the optimized set of decoupling capacitor assignments that satisfy the impedance mask you specify at the minimum cost.

Impedance and Cross-talk Scanning

The Zo and crosstalk scanner provides accurate field-solver characteristic impedances and coupling coefficients for traces within PCBs and packages. Easy-to-understand HTML reports and visualizations make this a must have sign-off capability for all design engineers.

Multidomain System Modeling

Simplorer is a powerful platform for modeling, simulating and analyzing system-level digital prototypes integrated with Ansys Maxwell, Ansys HFSS, Ansys SIwave, and Ansys Q3D Extractor. Simplorer enables you to verify and optimize the performance of your software-controlled, multidomain systems. With flexible modeling capabilities and tight integration with Ansys 3D physics simulation, Simplorer provides broad support for assembling and simulating system-level physical models to help you connect conceptual design, detailed analysis and system verification. Simplorer is ideal for electrified system design, power generation, conversion, storage and distribution applications, EMI/EMC studies and general multidomain system optimization and verification.

Features:

Electromigration Analysis

This new capability in Ansys SIwave allows you to predict mean time-to-failure for on-chip and advanced electronic packaging structures. Electromigration — migration of metal atoms in a conductor due to an electrical current — is typically not a problem in most electronics systems. However, in high-speed electronics, the increased performance and smaller form factors lead to increased current densities across very thin traces causing electromigration. This phenomenon is a major threat to the reliability of high-speed electronic products. Ansys SIwave can now predict electromigration and mean time-to-failure of a design.

EMI Solution

This capability provides automatic and customizable EMI design rule check of PCBs. EMI Scanner can quickly identify areas of potential interference on your PCB design prior to simulation. EMI issues traditionally have been difficult to simulate and require hours of computational time. This new feature included within Ansys SIwave and Ansys HFSS quickly identifies potential trouble spots that require further investigation. It eliminates errors and speeds time to market.

The EMI Scanner within Ansys SIwave and Ansys HFSS quickly identifies potential trouble spots and investigates them with proper what-if experiments for actionable design-rule violations in PCBs and packages, thus eliminating errors and speeding time to market. The EMI Scanner provides automatic and customizable EMI design rule checks of PCBs and quickly identifies areas of potential interference on PCB designs prior to simulation. EMI issues are traditionally difficult to detect and simulating these problems requires hours of computational time. EMI Scanner is fast, efficient and beneficial for identifying EMI problems so you can avoid costly testing and time-intensive simulations.

The EMI Xplorer complements the EMI Scanner in Ansys SIwave and Ansys HFSS and examines the shades of gray in a violation to determine how severe it might be. Depending upon the result of the analysis performed in EMI Xplorer, mitigation measures are taken in SIwave or HFSS as necessary. Many types of violations on a PCB are analyzed by the EMI Xplorer where you can easily adjust the design rule parameters or define additional rules as needed. It allows you to study the impact of rule violations on trace impedance, losses, edge current, noise voltage etc., without changing the original design. As an example, consider a critical net crossing a split in an adjacent reference plane. The design rule mandates adding at least two stitching capacitors within some maximum distance of the crossing. EMI Xplorer calculates the voltage across the split for the actual, desired and worst-case scenarios pertaining to the specified distance to the stitching capacitors. You can then perform multiple what-if experiments in EMI Xplorer to analyze these scenarios and ensure that the voltage across the gap is below the desired limit. EMI Xplorer minimizes potential board- and package-level EMI problems prior to running the final verification with time-consuming 3D simulations.