© 2011 autodesk simulation for electronics tom mello simulation specialist
TRANSCRIPT
© 2011 Autodesk
Simulation for Electronics
Tom MelloSimulation Specialist
© 2011 Autodesk
Informative Design PartnersCollaborative CFD consulting Provide insight from simulation to drive product development
Blue Ridge Numberics Inc.Develop, maintain, and support Cfdesign
Acquired by Autodesk Inc. 2011 Engineering Lead – Electronics Group
Focus on implementing simulation into the electronics product development process
Mupac, Carlo Gavazzi, SIE Computing SolutionsSpecialized in rugged electronic systems deployed in the worlds harshest environments Electronics packaging designer
CAD, CFD, & Physical testing
Speaker BIO
© 2011 Autodesk
Product Development Process Typical flow Cost
Time & Money
Simulation Technology Required resources Value
Return on Investment
Simulation in the product development process
Overview
© 2011 Autodesk
Product Inception
• Product Specifications
• Marketing & Sales Requests
Source Components
• Meet Specification• Cost• Lead Time
Package Components
• “Get everything in the box”
• Develop “envelope”
• Understand component relationships
Freeze Design
• Detail drawings• Send to
manufacturing
Product Development Process
Testing:
Pass or Fail?
FAIL: ECO
Produce Product
Prototype Cycle
© 2011 Autodesk
Prototype cycle How many cycles? How much time is allocated to test? 1-3 months?
Cost of Outsourcing Development
Outsourcing–Manufacturing
•Cost to change tooling•Cost to re-manufacture components•Turn around time
–Testing•Lab fees•Turn around time•Insight?
–Don’t meet specification! WHY?
Manufacture Parts
AssembleTesting:
Pass or Fail?
FAIL: ECO
Produce Product
© 2011 Autodesk
Example Outsourcing Development Costs
Service $ value Time Notes
Manufacturing :Rapid Prototyping
2-15k 2 weeks
Manufacturing :Tooling
10-60k 6 weeks Die-Cast
Manufacturing:Machine Shop
1-5k 2 weeks Typically Aluminum
Independent Laboratory 20-50k 3-5 weeks Specification validation, certification
Numbers taken from various actual product development outsourcing Costs can vary based on component material, size, complexity,…etc. Numbers meant to convey there is a COST to prototyping
Outsourcing manufacturing and product validation for a “prototype” (First off the line product) can cost 2-100K & up to 6 weeks! Important to get it right the first time!
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Manufacturing Cost of material Man hours
Each “round” of prototyping produces scrap material and wasted man hours
Manufacturing: In-house Product Development
CNC Sheet metal BrakePlastic Injection Molding
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Physical Testing Equipment
Don’t forget your lab coat!
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Physical Testing
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Correlation
High level of correlation Consider standard deviation / physical testing accuracy
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10
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Temperature Correlation
Simulation Physical Testing
°C
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Velocity Correlation
Physical Testing Simulation
LF
M
© 2011 Autodesk
Electronics Industry Mature
Digital prototyping common “Pushing the Envelope” with “State of the Art” technology
Introduces design challenges More Power Smaller Envelope! Specifications
Mil-spec, ATCA, compact PCI,…etc.
Implementation “Up Front” Design Verification
ATCA, compact PCI, ….etc.
Simulation
© 2011 Autodesk
Simulation Requirements Software
CAD & CAE Hardware
Examples: M6500 – 16 GB RAM Super Computer! Cloud
General understanding Historical product knowledge Proficiency with tools
“picks and clicks” Understanding of fundamentals
Fluid dynamics Heat transfer
𝑄=�̇�𝑐𝑝∆ 𝑡 𝑅=𝐿𝐾𝐴
𝑄=𝐾𝐴∆ 𝑡𝐿
𝑄=h𝐴∆𝑇
CatiaCoCreateInventor
NXPro/EngineerRevit
Solid EdgeSolidWorksSpaceClaim
© 2011 Autodesk
Upfront simulations 2D analyses
Identify variables Asses impact of modification
Positive or negative
Increase complexity Account for 3D phenomena Gain confidence in design as solution
Verify Design
Simulation Process Overview
You Are Here
Conceptual IdeaProject
Completion
• Traditional Design Verification– Dedicated analyst– Fully detailed CAD model– If design doesn’t meet specification
– Recall– Rework– More prototyping
Traditional Design
Verification
© 2011 Autodesk
Compress the process of development Non-simulation is a reactive process
design, test, iterate Time consuming and costly to represent products environment Results and conclusions are significantly limited
Simulation Easily define & vary product environment and operating conditions
Ambient temperature Heat dissipation to understand thermal cycling Passive or active cooling
Infinite number of thermocouples Thermal imaging camera output Can decrease product development prototyping time from weeks and months to days! Less scrap & man hours Increase product knowledge thought insight
Increase confidence in design Evaluate component reliability by understanding operating junction temperatures Optimize NOT OVER design!
Business Impact
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Real World Examples
ATR Design Evolution Cold Plate Design
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Design goals set by:1. Marketing
Standard product New market
2. Sales Customer requirements Cost concerns
3. Management (CTO, CEO, VP Engineering,…etc.) Company directives Technology driven
Considerations Form
Geometric envelope (HxWxL) System integration
Shelter Cabinet
Function Environmental concerns Milspec IO Packaged components
ATR Design Constrains
© 2011 Autodesk
Inlet & Outlet Momentum sources?
Fans at inlet and outlet? Location in chassis?
IO concerns Card Cage Power supplies
General System Layout
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Design Evolution
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2D Key Results
Highest velocities occur at fan max or min positions
Volume flow rate for all runs < 1% of each other
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Fan size and number
• Highest flow rate recognized with a single evacuation fan– Operating points (pressure rise and flow rate) are a function of system impedance
• less fans equates to less fluctuations in pressure field and less overall system impedance
• Is redundancy required?– If not; a reduction in complexity, manufacturing, & BOM costs are recognized with an increase in system performance by
eliminating inlet fan
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Intuitively makes sense Reinforce known phenomena
Flow fields, recirculation, stagnation
Identify relationships with geometry Inlet / Outlet positions vs. velocity & pressure drop
Guide fan selection Single evacuating fan
2D Discussion
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2D model drives 3D model Skeleton Layout “Master model” “Top down approach”
Increase complexity Add components
Baffles Metering Plates Heat Sinks
2D to 3D
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Main component of concern close to highest velocity in system
Main Component
Celsius Celsius Celsius Celsius CelsiusMain1 Max Temp Main2 Max Temp Main3 Max Temp Main4 Max Temp Main5 Max Temp
0
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5IN_5OUT6IN_6OUT
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Metering Plates Perforated metal plates Increase pressure drop across center
Air takes path of least resistance Promote flow to slots furthest from fan
Drive 2D analysis from 3D analysis Tune response of system
Increase Flow Uniformity in Card Cage Slots
© 2011 Autodesk
Tuning Metering Plates
© 2011 Autodesk
Power Supply Temperatures Exceeding maximum allowable operating temperature rise
Connect heat sinks in front of fan
Power Supply
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Objectives met Components operating below maximum allowable limits Cost reduced
Final Design
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Why? High power density Compact design
Applications Military Aerospace High-powered electronics Medical Numerous others
Main Types Internal Tube
Typically designed / developed by cold plate vendors Internal Fin
Cold plate vendors System level designers
Cold Plates
© 2011 Autodesk
Typical Design Constraints Maximum allowable operating temperature
limits Mounted components Internal ambient
Fluid Air Water Heat transfer fluid
EG WEG (50/50) Others
Fluid pressure drop Fluid temperature rise Cost Manufacturability
Design Variables Internal construction
“Folded” fin Machined fin
Speed & Feed # of “passes” Gap thickness Fin thickness Inlet / Outlet
Size location
Envelope Component “footprint”
Design
© 2011 Autodesk
Fluid gap size maintained Velocities consistent Isolate Conduction
More fins / less fins under chip Total conduction area Conduction paths
Bottleneck?
Machined Fin – Constant Fluid Gap SizeMachined Fin
Fin Thickness
Ch
ip T
em
pe
ratu
re R
ise
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Fin thickness maintained Isolate convection
Smaller Gaps Lower Temperatures Higher pressure drops
Fluid gap larger influence than fin thickness
Machined Fin – Constant Fin ThicknessMachined Fin
Fluid Gap Thickness
Ch
ip T
emp
erat
ure
Ris
e
Machined Fin
Fluid Gap Thickness
Pre
ss
ure
Dro
p
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Correlation between fluid spacing and temperature evident Higher velocities = lower temperatures & higher pressure drops
Fold Fin
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Product Development Process Typical flow Cost
Time & Money
Simulation Technology Required resources Value
Return on Investment
Simulation in the product development process
Discussion
© 2011 Autodesk
Informative Design Partners Collaborative consulting business model to
deliver CFD simulation services for confident design decisions.
Our model is built on leveraging strengths: The analysis process is left to our analysis
experts Design process is left to your design experts.
The insight we provide empowers our clients to create robust designs faster and more reliably without distractions to their current development process.
www.informativedp.com
© 2011 Autodesk
Questions?
© 2011 Autodesk
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Autodesk, AutoCAD* [*if/when mentioned in the pertinent material, followed by an alphabetical list of all other trademarks mentioned in the material] are registered trademarks or trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names, or trademarks belong to their respective holders. Autodesk reserves the right to alter product and services offerings, and specifications and pricing at any time without notice, and is not responsible for typographical or graphical errors that may appear in this document. © 2011 Autodesk, Inc. All rights reserved.