HFSS 3D Layout and the Phi Mesher

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HFSS Meshing TechniquesClassic• Approach: Starts with a 3D surface triangular mesh on all objects and generate a 3D volume mesh

throughout simulation domain• Availability: HFSS (traditional 3D interface) and HFSS 3D Layout• Pro: Works for any arbitrary 3D geometry• Con: For complex, many layered geometries can require a long time to generate

PhiNew

• Approach: From a layout, generate layer by layer 2D triangular mesh. Sweep mesh in stackup (+z) direction to generate tetrahedral mesh elements

• Advantage: Skips heavyweight ACIS and 3D surface mesh generation• Availability: HFSS 3D Layout only• Pro: Extremely fast relative to classic 3D mesh approach• Con: Only works for stack-up or ‘swept in Z’ geometries. IC components and packages, PCBs. etc.

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Why Phi?

Phi vs Classic• Always wins initial mesh generation

– Including Lambda + Port Adapt– Initial mesh size is comparable

• Can mesh bigger designs– When combined with distributed memory solver and hardware can solve very large

and complex designs

Initial Mesh is orders of magnitudes faster!

HFSS 15: 5hrs - Initial MeshHFSS 2014: 11min - Initial Mesh

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• Accurate Solution– Industry leading meshing capacity– Causal/Passive s-parameters– True DC solution– Embedded RLC or s-parameter components

• Fast Simulations– Reduces multi-day long simulations to a few

hours or less

• Ease of use – 3D Layout– Easy translation, import and setup– Maintains trace characteristics and nets from

layout– Hierarchical design – Chip/Package/Board– Embedded dielectric layers– Parameterized model for Design Optimization

• Trace width, layer thickness, via dimensions etc.• Manufacturing tolerances (etching factor)• Materials

Benefits of HFSS for 3D Layout

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HFSS 3D Classic – 5hrs 15min

HFSS 3D Layout w Classic v15 – 3hrs 41 min

• HFSS 3D Layout meshing advantages– Mesh and solve non-manifold geometry– Mesh geometries with large aspect ratios– Layer-based geometry is easier to edit,

modify, clean up etc.

Enhanced Meshing in HFSS 3D Layout

¼ of multilayer flip-chip package20 nets (40 ports)

HFSS 3D Layout w Phi – 11 min

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Is there a difference between HFSS 3D and HFSS 3D Layout ?

Solve a model in both HFSS 3D and HFSS 3D Layout and compare

Note easy export from HFSS 3D layout to HFSS 3D

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Multilayer complex package layout

• HFSS 3D compared to HFSS 3D Layout

HFSS 3D CAD

HFSS 3D Layout

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Initial Meshing Comparison

• Extremely fast initial Phi meshing. Phi is 20X faster!• 4min vs. 1hr 20min

HFSS 3D CAD - Classic

HFSS 3D Layout - PHI

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HFSS 3D – Run Time

• Total: 6hrs 33min• Adaptive Part: 4hr 1min• Interpolating Sweep: 2hrs 32 min

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HFSS 3D Layout – Run Time

• Total: 3hrs 3min• Adaptive Part: 1hr 05min• Interpolating Sweep: 1hr 58 min

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HFSS CAD vs. HFSS 3D Layout

Solid HFSS 3D CAD Dashed - - - - - - - HFSS 3D Layout

Virtually identical results from adaptive meshing

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Summary

HFSS 3D CAD HFSS 3D Layout

Initial Mesher Classic Phi

Initial Mesh Size (tets) 763, 953 712, 536

Initial Mesh Time 1hr 20min 4min

Number of Adaptive Passes 6 7

Number of Tets - Final 1, 617, 954 1, 620, 969

Adaptive Passes Run Time 4hrs 1min 1hr 5min (3.7X faster)

RAM 47.6 GB 49.6 GB

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Is there a difference between HFSS 3D and HFSS 3D Layout ?

Example #2: Multi-layer PCB with end to end SMA connectors

3D components drawn as stacked up geometry can be modeled in HFSS 3D Layout

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HFSS 3D Geometry• Include SMA connector body with stands (serve as ground pins)• Account for true 3D SMA transition to PCB

HFSS 3D Solid Model Design Creation

Lumped Port dimensions equal to connector pin dimensions

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Added SMA body geometry to a layout stackup

Port properties created automatically

HFSS 3D Layout Design Creation

Layout View

EM Design 3D View

Stackup EditorPort/pin settings

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Results Comparison

• HFSS 3D compared to HFSS 3D Layout

0.00 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00F [GHz]

-17.50

-15.00

-12.50

-10.00

-7.50

-5.00

-2.50

0.00

Y1

-62.50

-50.00

-37.50

-25.00

-12.50

0.00

Y2

EM with sma MOHFSS 3D CAD vs HFSS 3D Layout

Curve Info Y Axis

dB(S(1.TX_P2_in,3.TX_P2_out:T1))HFSS Setup 1 : Sw eep 1 Y1

dB(S(1.TX_P2_in_T1,3.TX_P2_out_T1))EM_w ith_sma_body_v8_EM_exported_v15_HFSSDesign1 : EM_w ith_sma... Y1

dB(S(1.TX_P2_in,1.TX_P2_in))HFSS Setup 1 : Sw eep 1 Y2

dB(S(1.TX_P2_in_T1,1.TX_P2_in_T1))EM_w ith_sma_body_v8_EM_exported_v15_HFSSDesign1 : EM_w ith_sma... Y2

Solid HFSS 3D CAD Dashed - - - - - - - HFSS 3D Layout

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Results Comparison – Return Loss

• HFSS 3D compared to HFSS 3D Layout

0.00 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00F [GHz]

-62.50

-50.00

-37.50

-25.00

-12.50

0.00

Y1

EM with sma MOReturnLoss

Curve Info

dB(S(1.TX_P2_in,1.TX_P2_in))HFSS Setup 1 : Sw eep 1

dB(S(1.TX_P2_in_T1,1.TX_P2_in_T1))EM_w ith_sma_body_v8_EM_exported_v15_HFSSDesign1 : EM_w ith_sma_body_v8_...

Solid HFSS 3D CADDashed - - - - - - - - HFSS 3D Layout

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0.00 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00F [GHz]

-17.50

-15.00

-12.50

-10.00

-7.50

-5.00

-2.50

0.00

Y1

EM with sma MOInsertion Loss

Curve Info

dB(S(1.TX_P2_in,3.TX_P2_out:T1))HFSS Setup 1 : Sw eep 1

dB(S(1.TX_P2_in_T1,3.TX_P2_out_T1))EM_w ith_sma_body_v8_EM_exported_v15_HFSSDesign1 : EM_w ith_sma_body_v8_...

Results Comparison – Insertion Loss

Solid HFSS 3D CADDashed - - - - - - - - HFSS 3D Layout

• HFSS 3D compared to HFSS 3D Layout

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Phi meshing is a breakthrough technology for finite element mesh generation

Provides designers of IC components, IC packages and printed circuit boards a faster initial mesh and faster simulation

Enables even larger and more complex layered geometries to be solved

When combined with ANSYS HPC can leverage scalable and fast HPC technologies

Distributed direct matrix solver to solve the largest design on distributed memory

Spectral decomposition method (SDM) to solve frequency points in parallel for faster simulations

Conclusions