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TRANSCRIPT
Trace Modeling
March 21, 2018
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Introduction
o Trace modeling is the process of creating more detailed
geometric models of the conductor regions, dielectric
regions, and laminate layers of a printed circuit board
for FEA rather than utilizing bulk PCB material
properties.
o Why model traces?
o PCB embedded technology
o Trace conduction analyses
o Microvia investigations
o Trace stress analyses
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PCB Layers - https://github.com/ArnieX/swifitch
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Top
Layer
Bottom
Layer
PCB Stackup
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Allow Image Conversion Debug Code
o Ensure the debug code for image conversion is applied.
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Conversion to Image Layer
o In the Sherlock circuit card “Files” tree, convert the Gerber layer of interest to an
image layer.
o Choose an appropriate resolution.
o NOTE: When Sherlock converts a Gerber Layer to an Image Layer, it overwrites
the original Gerber.
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Choosing an Image Resolution
o The most appropriate resolution will depend on specific
application and may require an iterative approach.
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10
PPI
100
PPI
500
PPI
1000
PPI
Generating a Trace Model
o In the Sherlock circuit card “Files” tree, generate a trace
model from an image layer of interest.
o Choose a Grid Size, Max Arc Segment, Min Trace
Area, and Min Hole Area.
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Choosing a Grid Size
o The “Grid Size” option specifies the resolution of the
trace model features. All coordinates are rounded to the
nearest grid unit.
o Use the finest grid unit option (0.0001 mm) for nearly
all cases.
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100 micron
Choosing a Max Arc Segment
o The “Max Arc Segment” option specifies the maximum length
of a segment generated when Sherlock converts arc drawing
commands to line segments.
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500 micron 1000 micron
Choosing a Min Trace Area
o The “Min Trace Area” allows the user to filter out traces that
are deemed to small to be relevant to the analysis.
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0 mm2 10 mm2 25 mm2
Choosing a Min Hole Area
o The “Min Hole Area” allows the user to filter out holes that
are deemed to small to be relevant to the analysis.
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0 mm2 10 mm2 500 mm2
Exporting a Single Layer Trace Model
o In the Sherlock circuit
card “Files” tree, export
a trace model for the
layer of interest.
o Export file type options
include:
o Abaqus python script
o ANSYS APDL script
o ANSYS CDB script
o Nastran bulk data file
o Calculix input script
o Step file
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Single Layer Step File
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o In the Sherlock circuit card “Analysis”
tree, export an FEA model from any of
the FEA tasks
o Natural Frequency
o Random Vibration
o Harmonic Vibration
o Mechanical Shock
Exporting a Full Stack Trace Model
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Full Stack Abaqus Model
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Questions?
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