ElectroFlo Rapid Virtual Prototyping for Thermal Analysis of Electronics
TES International Company Overview Established in 1994, TES is an engineering company committed to providing innovative and cost-effective solutions to challenging problems in the areas of heat transfer, CFD, stress and vibration All TES engineers hold advanced degrees in mechanical engineering with years of experience TES is a single source supplier providing turn-key solutions to aerospace, automotive and electronics industries
Numerical Solutions Group TES International State of the Art Computer Analysis Capabilities using MSC s Suite of Engineering Software, ANSYS, Mechanica and ElectroFlo, Fluent Focused on Providing Services to Ensure that our Customer s Product Meets the Intended Requirements Software Sales - ElectroFlo Designed Exclusively for Use by Engineers Faced with Challenging Electronics Cooling and Design Issues CFD Based Package Capable of Handling All Fundamental Modes of Heat Transfer Full List of Technical Features including Coupled Electrical/Thermal Analysis Capability Custom Solutions Group Process Automation and Methodology Standardization Provide Custom Software with Specified Graphical User Interface
Consulting Services - Sample Projects Automotive Electronics Collaborating with engineers and designers for thermal design and analysis of boards, boxes and systems and to develop processes for efficient thermal analysis; examples include: Bosch Power Train Micro-Hybrid Controller Chrysler Engine Controllers Chrysler Instrument Panel Junction Box Thermal Analysis Chrysler Seat Heater GM Transient Thermal Model for Fusible Link GM Thermal Design for Cooling of Luxury Car Alternators GM Battery Discharge Protection Module Delphi Electronic Power Steering Module Delphi Forward Looking Radar Thermal/CFD Study Delphi Coupled Electrical/Thermal/CFD Analysis of BEC s Siemens IDM2 Module Saturn Electronics Flex Board Coupled Electrical/Thermal Studies Visteon Molex Flexible Cable Connector Thermal Design Nortel GaAs Flip Chip Thermal Analysis Motorola/Ford Hydrocarbon Sensor
Consulting Services - Sample Projects Electronics Cooling Aircraft Work with customer engineers and designers for analysis and thermal design of boards, boxes and systems. Boeing 787 RFMC Controller- (Thermal) Hope-X APU Transient Thermal Analysis- (Thermal and CFD) Gulfstream Power Distribution Boxes - (Thermal and CFD) Hawker and Fairchild Secondary Power Systems - (Thermal and CFD) Comanche Helicopter Electronic Systems - (Coupled Electrical/Thermal/CFD) Joint Strike Fighter Cold-Plate Design (Thermal/CFD) F22 Generator and Bus System (Coupled Electrical/Thermal/CFD) Airbus Power System Bus Design (Transient Coupled Electrical/Thermal) Airbus Electronics Starter Controller (Transient Coupled Electrical/Thermal/CFD)
Consulting Services - Sample Projects Gas Turbine (Aircraft Engines & Power Systems) 9F, 7FB, 6FA+e, 9E (High Flow), 7FA+e GE Power System 3D Stator Thermal Models F101-102 Low Pressure Turbine Heat Transfer F110 High Pressure Turbine Stator and AFT Nozzle Thermal Model TF 34 HP Compressor Rotor Thermal Models J85 Turbine Thermal Model, Data Match and Missions GE90 Low Pressure Turbine Thermal Analysis T700 PT Rotor Thermal Model, Validation and Mission Analyses LM 2500 Low Pressure Turbine Thermal Analysis CF6-80C G2 Engine CRF Thermal Model CF34 HPT Rotor 3D Thermal Model of Bolted Joints F110-GE-129 Turbine Frame Heat Transfer Analysis TF39 LPT Case/Rotor Integrated Thermal Model F118-100 2D/3D Case Thermal Model and Analysis
Consulting Services - Sample Projects Structural/Vibrational Analysis Finite Element Analysis (FEA) services utilizing standard software such as Pro/Mechanica, Nastran or Ansys to analyze solid models for: Structural integrity of both linear and non-linear materials Modal analysis in consideration of vibrational characterization and performance in conjunction with standard Stress to Number of cycles (S/N) curves Motion analysis of drop tested or centrifugal dynamic systems, optimization of parts, components, systems and assemblies with respect to their associated performance and environmental specifications and requirements.
Summary TES is Focused on Providing Solutions in Thermal, CFD and Structural Engineering with a Focus on Electronics, Automotive and Aircraft Applications As a Partner, TES Can Supplement Analysis Capabilities Increase Productivity of the Engineering Staff Involve Customers in Software Development and Addition of Features of Interest (Customization / Enhancement Program) Some of the EFlo Features Resulting from Customer Involvement: Coupled Electrical/Thermal (Delphi Automotive, Hamilton Sundstrand) Heat Exchanger and Flow Networks (Hamilton Sundstrand) Thermoelectric Device (Eaton Corporation) Thermostat (Delphi Automotive)
Bussed Electrical Center (BEC) A power and signal distribution device where electrical switching and circuit protection components are combined into a single system. Contain components such as relays, fuses and circuit breakers, which are connected through an array of stamped metal bussing, traces and routed wires. The housing is made of a variety of molded plastic parts
Challenges Geometry Components, traces and other conductors from sources in various formats. Heat Generation Two main contributors: Component losses Joule dissipation due to current flow in traces and connectors Conjugate internal heat transfer Conduction Internal natural convection (using CFD) Internal thermal radiation Cooling to ambient Ambient natural convection and radiation
Electronic Device Models Typical components (relays and fuses) are geometrically and behaviorally too complex to be included in system model. Simple experiment-based device models are constructed to: Minimize the mesh requirement Capture the correct thermal behavior 1-D electrical links are used for electrical connectivity Material properties are adjusted to match thermal behavior of the simplified model to that of the tested device Library of device models created using simple geometry and producing accurate thermal behavior.
Electronic Device Models Heated Regions: q f T Electrical links to transfer current between elements; bypassing component details Fuse Model Relay Model
Electrical Conduction Regions A significant portion of the heat generated in the system is the Joulian heat due to electrical current flow in various traces and stamp metal conductors. 116 amps in Red : Main Circuit Gray: Secondary Circuits
Electrical Conduction Regions Trace and conductor geometry imported and simplified from CAD to EFlo using an automated procedure. A preprocessing tool, examines all elements and, using element electrical resistivity and electrical links, identifies individual conduction regions (circuits). The circuits are then displayed in different colors. Extensive tools are available for the user to examine various circuits and check for continuity and proper amperage.
Boundary Conditions The following types of boundary conditions are used to tie the model to its environment: Convection and Radiation to ambient Electrical boundary conditions (voltage and current BC s for Battery and connectors) Cable heat sinking BEC Walls: Convection and Radiation Battery Cable Voltage & Conduction BC s Cables: Current & Conduction BC s
Summary of the Solution Procedure 1. Initialize all Parameters 2. Solve for the initial voltage field 3. Obtain the initial Joulian heat dissipation 4. Solve for temperature and flow fields 5. Update Material Properties 6. Solve the electrical field and update power dissipation 7. Solve the radiosity matrix, calculate net outgoing radiation for all participating surfaces and adjust surface element source terms 8. Solve for temperature and flow 9. Return to Step 5 and Iterate until convergence
Results Temperature Distribution
Results: Conductor Temperature
Remarks This study points to a large class of electronics applications that require the coupled solution of heat transfer, flow and voltage fields. Without this coupling, the model would give misleading results. The ability to more closely simulate reality results in not only better reliability of the circuits, but also may allow a substantial cost savings.
Seat Heater Thermal Analysis Ambient Conditions: Ambient Temperature = 25 C Natural Convection Current Out Current In
Temperature Distribution
Detail Model
Results: Detail Model
Results: Detail Model
Transient Coupled Analysis Natural convection cooling of 6-layer board Internal copper layers Vias (both electrical and thermal) Electronic components A simplified version of a typical aircraft electronics board is studied. The impact of coupling the thermal and electrical solutions for a given circuit board is demonstrated to be important for the accurate prediction of temperature profiles.
Problem Description Enclosure 6.4 in x 3.9 in x 1.4 in Aluminum Case Model Steady State and Transient Analyses Six-Layer Board Ten Components g Environment Natural Convection T amb = 70 C Load Current = 200 amps Total Capacitors Terminal Blocks
Circuit Board Details Vias Board 5 in x 3.5 in x 0.09 in Copper Layers 0.005 in Thick 3 Load Layers 3 Return Layers Vias Connecting Layers 0.00125 in2 Load Terminal Blocks Copper Return Terminal Blocks
Steady-State Results
Board Temperature after 2 Minutes Coupled Max Temperature = 120 C Julian Heat Dissipation = 10.2 Watts Predicts Failure Uncoupled Max Temperature = 112 C Julian Heat Dissipation = 8 Watts Predicts Safe Design
Transient Results Temp (C) 120 110 100 90 80 70 Effect of coupling Thermal and Electrical Simulation T Max T Max (no coupling) T Min T Min (no coupling) 0 20 40 60 80 100 120 Time (s) As temperature increases the electrical resistance increases, causing higher heat dissipation.
Voltage Field Load Layer Return Layer
Aircraft Electronic Box with Plug-in Modules System and Board Analyses Modeled as Sealed Enclosure with Cold Plated Sidewalls Air Enters Heat Exchangers at 57 C Heat Exchangers were Modeled Using EFlo Heat Exchanger Feature Boards (removed) Air Inlets Air Outlets System Level Analysis PWB Analysis Provide B.C.
System Model : Aircraft Electronic Box with Plug-in Modules System and Board Analyses EFlo s Heat Exchanger Feature Used to Model Two Cold-Plated Sidewalls Determine Cooling Air temperature and Temperature Distribution for Daughter Boards Mother Board Model: 14 4-Oz Copper Layers Modeled (Uniform FR4 Layers Between Copper Layers) Thermal Boundary Conditions Provided by System Model The Two Models Were Analyzed in Parallel System Level Analysis Board Analysis Linked
Aircraft Electronic Box with Plug-in Modules System and Board Analyses Sidewall Temperature Distribution
Aircraft Application - Thermal Analysis (PSC1/2) Daughter Board Analysis Description of Plug-in Board model: Board Total Dissipation = 24.25 W 12 Copper Layers Modeled: All Layers are 2 oz Copper Uniform FR4 Layers Between Copper Layers Thermal Vias: Unfilled Copper Cylindrical Shells Diameter = 0.028 in Wall Thickness = 0.0014 in Board Wall Contact: Contact Length = 4.275 in (i.e., Board Height) Contact Width = 0.24 in Contact Rth = 2 C in/w
The Mother Board Electrical/Thermal Analysis Coupling Between System Model and Mother Board Model 10 Copper Layers Modeled: All Layers are 4-oz copper Uniform FR4 Layers Between Copper Layers Spacing Between layers = 3.5 mils Connectors Board Wall Contact: Contact Length = 0.5 in Contact Width = 0.5 in TB1 TB2
Aircraft Electronic Box with Plug-in Modules System and Board Analyses
Voltage Field (Layer 5)
Aircraft Electronics - Power Distribution Box Thermal Design Analysis Type: Conjugate Heat Transfer Analysis Type: Conjugate Heat Transfer Volumetric Flow Rate = 60 CFM Total Volumetric Flow Rate = 60 CFM Total Average Inlet Velocity = 0.63 m/sec Average Inlet Velocity = 2.74 m/sec DC Contactors AC Contactors DC Contactors AC Contactors LPDB RPDB
LPDB DC Board
LPDB AC Board
RPDB DC Board
RPDC AC Board
Starter-Generator: DC Link/Diagnostics Board Ambient Temperature = 85 C Initial Temperature = 85 C Simulation Time = 120 sec 6 Copper Layers Modeled: Layers 1 and 6: Layers 2 Thru 5: 0.0037 inch Thick 0.0048 inch Thick Uniform FR4 Layers Between Copper Layers = 220 kg/m 3 C P = 840 J/kg.K Thermal Vias: k = 0.157 W/m.K Air Filled Copper Cylindrical Shells 0.0036 inch Wall Thickness
APS 2300 DC Link : Results Capacitor, Current 4.45 A in or out from top and bottom Capacitors 71.2 A in 71.2 A in 71.2 A out 71.2 A out Temperature Distributions (After 2 min.)
Aircraft PWD: Model Description Cases Analyzed: 1. Normal Operation: Forced Flow (0.00115 Kg/s) Ambient at 50 Cooling Air at 40 C 2. Loss of Cooling: Ambient at 70 ; Cooling Air at 70 C Transient Natural Convection 30 Minutes; Starting from Case1 3. Worst Case: Ambient at 70 C; Cooling Air at 70 C Natural Convection Steady State Input Board Cooling Air Out Convection Applied to These Two Walls Only Output Board Digital Board Cooling Air In
Case3: 3D Temperature Plot Natural Convection with Cooling Holes Ambient Temperature = 70 C Cooling Air Temperature = 70 C
Case3: Temperature and Flow Results Natural Convection with Cooling Holes Ambient Temperature = 70 C Cooling Air Temperature = 70 C Flow Rate Thru System = 8.4x10-4 Kg/sec