LuxPCB Thermal User Guide

8/6/2019 LuxPCB Thermal User Guide

http://slidepdf.com/reader/full/luxpcb-thermal-user-guide 1/70

LuxPCB ©

Instruction ManualV 1.4.0

Lux Engineering Analysis, Inc.

Thermal


http://slidepdf.com/reader/full/luxpcb-thermal-user-guide 2/70uxPCB User Guide

Copyright © 2011 Dunamis Technology Incorporated. An affiliate of Luxea, Inc.All rights reserved.

Luxea © LuxPCB © Thermal User Guide for Windows ®

If this guide is distributed with software that includes an end user agreement, this guide, as well as the software described in it, is

furnished under license and may be used or copied only in accordance with the terms of such license. Except as permitted by any

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as a commitment by Dunamis Technology Incorporated. Dunamis Technology Incorporated assumes no responsibility or liability for

any errors or inaccuracies that may appear in the informational content contained in this guide.

Please remember that existing artwork or images that you may want to include in your project may be protected under copyright

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Please be sure to obtain any permission required from the copyright owner.

Any references to company names in sample templates are for demonstration purposes only and are not intended to refer to any

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http://slidepdf.com/reader/full/luxpcb-thermal-user-guide 3/70uxPCB User Guide 3

Welcome to Luxea’s LuxPCB © Thermal, and thank you for purchasing our software.

LuxPCB © Thermal is a performance focused, FEA basedanalysis tool for PC boards. Based on Luxea’s powerful LibraFEAengine and over 100 years of combined experience andexpertise, LuxPCB features streamlined, intuitive, and powerfulanalysis package that provides rapid solutions for pre-optimization to verification process in PCB design. LuxPCBfocuses on efficiency, so that you can spend time getting

results, not learning how to use the software or building the PCBmodel.

Tools are vital if engineers are to improve efficiency, achieveaccurate results, and maximize overall performance. That’s whywe take a great deal of pleasure in creating software thatreally works for engineers and helps them with their tasks.

We hope to continuously serve engineers and would again, liketo thank you for purchasing Luxea, Inc. products.

The Luxea Team

About LuxPCB Thermal



1 Installation Step by Step Guide ……………………………….......................

2 LuxPCB © Thermal Overview LuxPCB © Menu at a Glance ……………………........................... LuxPCB © Menu in Detail ….…………………………………..........

3 Settings General Option .......................................................................... Analysis Settings ………………………………............................

• Convection ……………………………………………….......

• Units ………………………………………….........................

4 Model Building PC Board Modeling ……………………………............................

Component Modeling ………………………………………...........

Cold Plate Modeling ………………………………………….........

Conduction Bar Modeling …………………………...…………......

Boundary Conditions ……………………………….......................

5 Results Analysis ………………………………….......................................

Jplot Results .............................................................................. Report Generation ………………………………….......................

11

7

910

1920

22

2429

353943

46

4953

17



6 LuxCalc Tools h Calc ……………………………..................................................

Board K …………………………………………….......................

7 Appendix Key Terms ……………………………..........................................

5863

67



Installation

1

Step by Step Guide



1. Run LuxPCBSetup.msi

2. Follow the steps

1 2

3

(LuxPCBSetup.msi)

Step by Step Guide

7

LuxPCBSetup

4

5 6



LuxPCB © ThermalOverview

2

LuxPCB © Menu at a Glance LuxPCB © Menu in Detail



A. Program Control ToolsIncludes LuxPCB function controlling buttons

B. LuxCalc ToolsIncludes LuxCalc calculator tools for ‘h’ and ‘Board k’

C. Model Building ToolsIncludes PCB model building buttons

D. Model Display/Interface WindowDisplays interactive model of the PCB

D

A

C

LuxPCB © Menu at a Glance

B

9



A

LuxPCB © Menu in Detail

1. FileManage LuxPCB sessions

2. Edit ImageManage imported image files

Program Control Tools

5 6 7 8 9 10 11

1 2 3 4

• New Project: Starts new project

• Open Project: Opens saved project

• Save: Saves current project• Save As...: Saves current project as

• Exit: Exits LuxPCB

• Add Image: Adds PCB image from file• Clear Image: Clears PCB image

• Crop Image: Crops PCB image




3. ToolsAccess material library, Jplot, FEAinput file, and general options

4. HelpAccess User Guide and informationabout LuxPCB

5. RunInitiate analysis

6. Model CheckCreate and display 3D renderedmodel of PCB in Jplot

• Material Library: Opens materiallibrary

• Model Viewer: Opens the latestgenerated PCB model in Jplot

• FEA Input File: Opens input text fileused by LuxPCB FEA engine

• Options: Opens directory setting andmodel analysis setting

• Help: Opens help

• About...: Displays program versioninformation



7. SettingSet analysis mode

8. UnitsSet units of variables and constants

9. PCB ImageImport PCB image file

10. LibraryAccess and manage materials library for PCB model

11. ReportManage the format and images to include in the automaticallygenerated Power Point report




B

12. h CalcConvection h calculator tool

13. Board KBoard k calculator tool

LuxCalc Tools


12 13



C Model Building Tools

14. Select PointerSelect PCB model parts

15. Create/Modify PC BoardCreate or modify PC board

16. Create/Modify ComponentCreate or modify component

17. Create/Modify Cold PlateCreate or modify cold plate

18. Create/Modify Conduction BarCreate or modify conduction bar

19. Define Boundary ConditionsCreate and define boundary condition

14

15

16

17

18

19




D

20. Primary / Secondary SideSelect between primary and secondary side of PC board

21. Coordinate Axis OrientationView x-y axis orientation of PCB model

22. Status LineView current mode and analysis progress information

23. X & Y coordinateView x and y coordinate of pointer relative to PCB model

Model Display/Interface Window

20

21

22

23




Settings

3

General Options Analysis Setting



1. Press Tools > Options

2. Set the values for the followingtabs:

a. Generalb. Model Options

General Options

17

a. b.



Options

a. General

Set the location of thedirectories

Note: By default, the location of thedirectories are in C:\LuxPCB

b. Model Options

Set the detail level of theanalysis

Note: In Component Detail- Coarse = 50% of the Grid Detail- Normal = 100% of the Grid Detail

- Fine = 200% of the Grid Detail

Note: Grid Detail signifies the number ofgrids along the shorter side of theboard

General Options



1. Press Setting

2. Set the values for the followingtabs:

• Convection• Units

Analysis Setting

19



Convection

1. Select Analysis Type

Note:- For convection analysis, check thebox- For conduction analysis uncheckthe box

2. Select Natural Convection orForced Convection

1.

2.

Natural Convection

1.

2.

3.

1. Select global ‘h’ application

scope

Note: If none are selected, h value willbe set to ‘0’ (no global convection

effect; set the convection effectslocally)

2. Select air flow orientation

3. Enter ambient (air) andestimated surface (PCB)temperature of PCB primaryand secondary side

Analysis Setting



Forced Convection

1. Select global ‘h’ application

scope

Note: If none are selected, h value willbe set to ‘0’ (no global convection

effect; set the convection effectslocally)

2. Set airflow direction

3. Enter airflow rate

4. Enter duct dimensions

5. Enter total heat input(dissipation) on the PCB

6. Enter inlet ambient airtemperatures for primary andsecondary side of PCB

7. Select type of boundarycondition for Nusselt numbercalculation

Note:

- Uniform heat flux: average Nusseltnumber for uniform heat flux in flowdirection and uniform walltemperature at any cross section

- Uniform wall temperature: averageNusselt number for uniform walltemperature

1.

2.

3.

4.

5.

6.

7.

Analysis Setting



Units

1. Select units system for each ofthe constants and variables

Note: Units System are available in SI,Mixed, and Imperial

Analysis Setting



Model Building

4

PC Board Modeling Component Modeling Cold Plate Modeling Conduction Bar Modeling Boundary Conditions



1. Press PCB Image (optional)

Note: Steps 1 to 3 are optional (loading aPCB image file to sketch on)

2. Select image file

3. Image file loaded

PC Board Modeling

24



4. Press Create/Modify PCB Board

Note: When building a model on an

image, do not adjust the LuxPCBwindow size after the first sketchhas been made as it willmisalign the image with thesketch

5. Click and drag to createboard

6. Board is created and EditProperties windowautomatically pops up

PC Board Modeling



7. Geometry/Heat Tab:

Enter heat (optional) anddefine board geometry

a. Heat

Note: Equivalent smeared total heatdissipation for the PCB

b. Geometry

8. Material Property Tab:

Choose amonga. Libraryb. Select Commonly

Usedc. Manual inputd. Calculate K

to define PCB layerproperty

a. b.

c.

d.

a.

b.

PC Board Modeling

26



Material Property

a. Library

Select from file or managestored entries (create new ordelete)

b. Select Commonly Used

Select from the list

c. Manual Input

Enter values directly

PC Board Modeling



d. Calculate K

Calculate the equivalent K of aboard by defining the Material

Property and PCB Stackupinformation

Layer Detail:

Enter the values for the

number of layers, thicknesses,and fill percentages of each ofthe layers

PC Board Modeling



Component Modeling

1. Press Create/Modify Component

2. Click and drag to createcomponent

Note: PC Board must be drawn first

3. Component is created

CMP_t_0

29



4. Double click on componentto edit properties

5. In the Cross Sectional View,select layer

a. Component

b. Board Interfacec. PCB with Vias

Note: If ‘Convection’ is selected in

the ‘Analysis’ setting, an

interactive red arrow will bedisplayed

Natural Forced

Select to adjust the ‘h’ value of

the air flow

6. Select Geometry/Heat Tab:

Enter heat and definegeometry and location

a. Cold Plateb. Detail

CMP_t_0

a.b.c.

a.b.

Component Modeling



Geometry/Heat

a. Cold Plate

Connects the component tothe cold plate (if available)

Note: A new connection layer (Cold PlateInterface) will be available to assignproperties

b. Detail

View the detailed cavityconfiguration of thecomponent

Note: New layers (ComponentEncapsulant and ComponentSubstrate) will be available toassign properties

Note: Cavity configuration can beswapped

Component Modeling



7. Select Material PropertyTab:

Choose among

a. Libraryb. Select Commonly

Usedc. Manual inputd. Calculate K

to define property

Note: Calculate K is only availablewhen ‘Board Interface’ or ‘PCB

with Vias’ is selected

Note: If the thickness of a part issignificantly smaller than that of

the board, the part will berepresented with a triangle

a. b.

c.

Component Modeling

d.



Material Property

a. Library


b. Commonly Used List


c. Manual Input


Component Modeling



d. Calculate K

Calculate the equivalent K of a‘Board Interface’ or ‘PCB with

Vias’ by defining the leads or vias information

Board Interface:

Enter the values for the leadsproperties and the interface

Note: Material properties can beimported from the library

PCB with Vias:

Enter the values for the viasproperties

Note: Material properties can be importedfrom the library

Component Modeling



Cold Plate Modeling

1. Press Create/Modify Cold Plate

2. Click and drag to createboard


3. Cold Plate is created

35



4. Double click on cold plateto edit properties

5. Choose cold plate in theCross Sectional View to

enter ‘Geometry’ and‘Material Property’

Note: If ‘Convection’ is selected in

the ‘Analysis’ setting, an

interactive arrow will bedisplayed

Select to adjust the ‘h’ value of

the air flow

Natural Forced

6. Geometry Tab:

Enter geometry andlocation properties

Cold Plate Modeling




Choose amonga. Library

b. Select CommonlyUsed

c. Manual input

to define property

Note: The PC Board properties can

be edited by selecting the PCBoard layer in Cross SectionalView

Note: To connect cold plate tocomponent, click on thatcomponent and check the ‘Cold

Plate’ option (See Component

Modeling for more details)

a. b.

c.

Cold Plate Modeling



Material Property

a. Library




c. Manual Input


Cold Plate Modeling



Conduction Bar Modeling

1. Press Create/Modify Conduction Bar

2. Click and drag to createconduction bar


Note: Conduction bar must notoverlap with components

3. Conduction Bar is created

39



4. Double click on conductionbar to edit properties

5. Choose the conduction barin the Cross Sectional View

to enter ‘Geometry’ and edit‘Material Property’

6. Geometry Tab:

Enter geometry properties





Choose amonga. Library

b. Select CommonlyUsed

c. Manual input

to define property

Note: The PC Board or Cold Plate

properties can be edited byselecting the PC Board or ColdPlate layer in Cross SectionalView

a. b.

c.




Material Property

a. Library




c. Manual Input





Boundary Conditions

1. Press Create/Modify Conduction Bar

2. Click and drag to createboundary condition


Note: The nodes that are enclosedwithin the boundary region are

set to the specified conditions

3. Boundary Condition iscreated

43



4. Double click on boundarycondition to edit properties

5. Enter boundary regionproperties

Boundary Conditions Modeling



Results

5

Analysis Jplot Results Report Generation



1. Press Model Check (Optional)

Note: Steps 1 and 2 are optional (Checkthe model of your PCB in 3D modelprior to running analysis)

2. 3D rendered model of PCBshown in Jplot

3. Press Run

Analysis

46



Analysis

4. Analysis progress bar

5. 3D color contour result inJplot

6. Modify result with variousviewing modes and tools inJplot



Analysis

7. Save result image by pressingSave Image to Report

8. Enter title for the image

Note: The saved images will be storedin C:\LuxPCB\workspace (or thedesignated directory set in GeneralOptions) and used in the ReportGeneration



Jplot Results

49

D

A

C

B

A. Program Control ToolsIncludes Jplot function controlling buttons

B. Temperature Unit SettingDisplays currently selected temperature unit

C. Temperature Color KeyDisplays temperature variations

D. Result Display WindowDisplays the color contour plot of the PCB in 3D



A

1. FileManage sessions of Jplot

2. ViewManage result image

Program Control Tools

5

6 7 8 9 10 11

1 2 3 4

Jplot Results

12 13 14 15 16 17

• Set Directory: Designates directory tosave captured images to

• Exit: Exits Jplot

• Reset: Resets the view to the default

• Zoom: Zooms in or out

• Set Rotation: Specifies the x and yviewing angle ( e.g. x30y60)

• Orthogonal View: Selects predefinedviewing angles

• Auto Rotate: Auto rotates the 3D PCBmodel when model is clicked

• View Option: Selects the parts of thePCB model to view



Jplot Results

3. ContourSelect contour mode of the PCBmodel

4. OptionsAccess plot option

5. HelpAccess LuxPCB User Guide andinformation

6. Save Image to ReportSave current result view for ReportGeneration

7. Return to Full ViewReset result view to default view

8. Select Area to Zoom InDefine area to zoom in

• Help: Opens up help

• About...: Displays program information

• Normal: Monochrome 3D rendered model

• Wireframe: Wireframe 3D rendered model

• Material: Color part distinguished 3Drendered model

• Thermal: Color temperature distinguished3D rendered model



9. Zoom InZoom in current result view

10. Zoom OutZoom out current result view

11. Isometric ViewDisplay result view in isometric

12. View from positive x axisDisplay result viewed from + x axis

13. View from negative x axisDisplay result viewed from - x axis

14. View from positive y axisDisplay result viewed from + y axis

15. View from negative y axisDisplay result viewed from - y axis

16. View from positive z axisDisplay result viewed from + z axis

17. View from negative z axisDisplay result viewed from - z axis

Jplot Results



1. Press Generate Report

Note: Units and formats of theautomatically generated report willfollow those in the analysis settingsimmediately before the last analysisRun.

2. Set values for the followingareas:

a. Add Contour Plotsb. Select Slidesc. Options

Report Generation

53

c.

a. b.



Report Generation

Generate Report

a. Add Contour Plots

Select the previously savedimages (from Jplot) from thelist or import images toinclude in the report

Note:- The titles of the previously savedresult images from Jplot will belisted in the left window

- Import image files from an external

source with the Import button (theimported files will be listed in theleft window)

- Move the desired images from theleft window to the right window toinclude in the report

- In report, the images will bedisplayed in the order listed from

top to bottom



Report Generation

b. Select Slides

Select preformatted resultslides to include in the report

Note: If Component Sketch box ischecked, the program will promptyou to select the external image youwould like to include in the reportafter Generate Report button ispressed

The image selection window willpop up after you designate the

name and location of the report tobe generated

c. Options

Enter report information



Report Generation

d. Press Generate Report

e. Designate the save location ofreport

f. Power Point report created



LuxCalc Tools

6

h Calc Board K



A. Convection TypeSelect type of convection

B. Input SettingsDefine convection input parameters

C. Results SummaryDisplays the results

AC

h Calc

B

58



Natural Convection

1. Select Natural Convection

2. Enter convection inputparameters

3. Press ‘Calculate’ button

h Calc



h Calc

4. Results are displayed



Forced Convection

1. Select Forced Convection

2. Enter convection input

parameters

3. Select type of boundarycondition for Nusselt numbercalculation

Note:

- Uniform heat flux: average Nusseltnumber for uniform heat flux in flowdirection and uniform walltemperature at any cross section

- Uniform wall temperature: averageNusselt number for uniform walltemperature

h Calc



h Calc

4. Press Calculate




A. Material SelectionDefine material properties of the board

B. Input SettingsDefine PCB stackup information

C. ResultsDisplays the results

A

C

Board K

B

63



Board K

1. Material Property:

Choose among

a. Libraryb. Select Commonly Used

2. Define PCB stackupinformation:

Layer Detail:

Enter the values for thenumber of layers, thicknesses,and fill percentages of each ofthe layers

a.b.



Board K

3. Press Calculate


Note: The results are also calculatedwhen Ok button is pressed in LayerDetail window

Note: The results can be saved to thelibrary



Appendix

7

Key Terms



Key Terms

PCBPrinted Circuit BoardA board that is used to mechanically support and electrically

connect electronic components using conductive pathways,tracks or traces etched from copper sheets laminated onto anon-conductive substrate.

ComponentA logical unit of structure that includes integrated circuit chipand packing. The interfaces to the PCB and coldplate(optional) is included in the model

1. Component SubstrateA logical unit that represents a combined unit of the dieof integrated circuit chip and a substrate

2. Component EncapsulantA molding that is used to cover the die and the rest ofthe substrate to provide protection to the die from theenvironment.

3. Board Interface

Accounts for leads and thermal pad or air gap betweenthe component and PCB

4. PCB with ViasThe part of PCB underneath the component thatincludes through-hole vias. The effect of vias arereflected in the modified value of K in z-direction only.The modified and orignal K value are smeared usingweighted area rule and the effective Kz value is used for

the area underneath each component.

Cold plateA solid plate made of highly conductive material that isconnected to the component with the purpose of providingadditional heat flow paths.



Conduction barA solid block of highly conductive material that connects acold plate to a PCB.

Boundary Region

A region of model in which specified conditions are enforcedon the enclosed grid point.

hConvective coefficient. An average convection heat transfer coefficient over an area.

Thermal resistance

A property which indicates a material's ability to resist the flowof heat k Thermal conductivity. The property of a material thatindicates its ability to conduct heat. A reciprocal of thermalresistance.

Natural convectionA mechanism, or type of heat transport in which the motion ofthe fluid is caused solely by differences in density resulting from

temperature gradients and is not aided by a pump or a fan.

Forced convectionA mechanism, or type of heat transport in which fluid motion isgenerated by an external source (like a pump, fan, suctiondevice, etc)

Steady State

A state of a system, in which the recently observed behavior of the system will continue into the future.

TransientA state of a system, in which a process variable has beenchanged and they system has not reached steady state.

Key Terms



2-D boardRepresentation of a board using two-dimensional shell model

3-D boardRepresentation of a board using three-dimensional solid model

Thermal AnalysisA type of analysis where the change of temperature in thesystem is simulated, subject to given set of boundaryconditions

Stress AnalysisA type of analysis where the change of stress in the system is

simulated, subject to given set of boundary conditions

Ambient temperatureThe temperature of the surrounding condition, usually definedas room temperature. Ambient temperature is subtracted fromestimated surface temperature in order to determinetemperature gradient

Estimated surface temperatureEstimated, average surface temperature. Ambienttemperature is subtracted from estimated surfacetemperature in order to determine temperature gradient

Air flow directionDirection of incoming airflow

Air mass flowTotal amount of air mass moving through a unit surface per unit time

CFMCubic feet per minute. A non-SI unit of measurement of flow ofgas or liquid in a given amount of time.

Key Terms


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Heat input

Heat dissipation in the component

Nusselt equation

Dimensionless heat transfer coefficient. For forced convection,

different equations are used for different boundary conditions :

1. NuH Average Nusselt number for uniform heat flux inflow direction and uniform wall temperature at anycross section

2. NuT Average Nusselt number for uniform walltemperature

ReReynolds Number. A dimensionless parameter thatquantitatively relates the viscous and inertial forces and whosevalue determines the transition from laminar to turbulent flow

≝ ρ U∞ x ⁄ μ = U∞ x ⁄ ν

Gr

Grashoff Number. Ratio of buoyant to viscous forces

≝ g β (T s-T ∞ ) L3 ⁄ ν 2

Pr

Prandtl Number. Ratio of molecular momentum diffusivity tothermal diffusivity

≝ Cp μ ⁄ k = ν ⁄ α

Key Terms

LuxPCB Thermal User Guide

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