WORKSHOP 9 THERMAL ANALYSIS OF THE HYBRID MICROCIRCUIT

WS9-2 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation

WS9-3 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Model Description In this exercise complete the analysis of a hybrid microcircuit which is subjected to a bench functional test. The hybrid is clamped to a test fixture which is chilled by iced water. The microcircuit is continuously flushed by a dry nitrogen purge at 21°C. During functional testing, which takes approximately 1hour, the entire hybrid dissipates 8watts. Each device dissipates a constant wattage, as listed. The goal of the analysis is to verify that all device temperatures remain below 50°C.

WS9-4 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Hybrid Microcircuit Boundary Conditions

WS9-5 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Objectives In this exercise you will complete a steady state thermal analysis of the 3D hybrid microcircuit. Exercise Overview 1. Open the existing database named microcircuit.db. 2. Use Finite Elements/Create/Node/Edit to create the two fixed temperature boundary nodes. 3. With Display/Finite Elements…. Or the equivalent Tool Bar function increase the display size of nodes to facilitate boundary definition. 4. Use Loads/BCs/Create/Temperature/Nodal with Option: Fixed to set the boundary node temperatures. 5. Use Loads/BCs/Create/Convection with Option: Fixed Coefficient to apply the contact and nitrogen flow heat transfer coefficients. 6. Post only the device_and_solder group and use the middle mouse button or various Viewing functions to expose the individual device surfaces. 7. Use Loads/BCs/Create/Heating with Option: Template, Volumetric Heat to apply the heating load to the individual devices. 8. Select Analysis to prepare and to submit the model for analysis and to Read Results. 9. Post hybrid_fem, select an isometric_view, select Results, and review results data. 10. Quit MSC.Patran.

WS9-6 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 1: Open an Existing Database Open the existing database a. Select File from the Menu Bar b. Select Open from the drop down menu. c. Select the name microcircuit.db. d. OK. a b c d

WS9-7 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create 2 Boundary Nodes Create the two fixed temperature boundary nodes. a. Select Viewing. b. Click Named View Options… c. Under Select Named View, select side_view. d. Select the fit_view icon e. Close. b e a c d

WS9-8 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create 2 Boundary Nodes Create the two fixed temperature boundary nodes. Create two nodes that are not associated with geometry. a. Finite Elements. b. Create/Node/Edit. c. Under Node ID List enter d. Deselect Associate with Geometry. e. Under Node Location List enter [ ]. f. Apply. g. Repeat these steps for Node 9999 using the location [ – 0.007]. a b c d e f

WS9-9 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 3: Change Display and Picking Increase the display size of nodes and set the picking preferences to facilitate boundary definition. a. Select Display. b. Click on Finite Elements… c. Use slider bar to select 6 for the Node size. d. Click Apply. e. Select Preferences. f. Click on Picking from the Preferences drop down menu. g. Select Enclose Centroid. h. Close. a b c d g h f

WS9-10 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Select Display/Load BCs/ Element Props/ Vectors… to facilitate viewing boundary conditions. a. Select Display. b. Select Load/BC/ Elem. Props… c. Deselect Show LBC/ El. Prop Values. d. Click on Vectors/Filters… e. Under Scale Factor, enter f. Apply. g. Cancel. h. Apply. i. Cancel. a b c d e f h Step 3: Change Display and Picking

WS9-11 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 4: Fix Nodal Boundary Temperature Fix the boundary node Temperatures. a. Loads/BCs. b. Create/Temperature/ Nodal. c. Select Fixed Option. d. Under New Set Name, enter Cold_plate. e. Select Input Data… f. Under Fixed Temperature enter 0.0 g. Click OK. h. Select Select Application Region. i. Click on FEM. j. Select Node 9999 under Select Nodes. k. Click Add, OK, then Apply. l. Repeat this procedure for New Set Name Nitrogen with a fixed temperature of 21.0 applied to Node a b c d e f g h i j k Note: the display should highlight each node and append the fixed temperature. On some displays the symbol and value may be difficult to discern. k k

WS9-12 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 5: Apply Convection Boundary Conditions Apply contact and nitrogen flow heat transfer coefficients. a. Loads/BCs. b. Create/Convection/ Element Uniform. c. Select Fixed Coefficient for Option. d. Enter nitrogen_flow for New Set Name. e. Select 3D for Target Element Type. f. Select Nodal for Region 2. g. Click on Input Data… h. Enter 8.0 for Convection Coefficient. i. OK. (continued) a b c d e f g h i

WS9-13 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Apply contact and nitrogen flow heat transfer coefficients. a. Under Loads/BCs click on Select Application Region… b. Click on FEM Filter. c. Under Application Region select all top and all side free faces by dragging a rectangle around them. d. Add. e. Under Coupling Region select Node f. Add. g. OK h. Apply. a b c f h g c d e Step 5: Apply Convection Boundary Conditions

WS9-14 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 5: Apply Convection Boundary Conditions Repeat this process for a New Set Name. a. Type in heat_sink for New Set Name. b. Click on Input Data… c. Enter for Convection Coefficient. d. Click OK. e. Click on Select Application Region… f. Click on FEM. g. Under Application Region, select all bottom free faces by dragging a rectangle around them (as shown). h. Click Add. i. Under Coupling Region select Node j. Add. k. OK. l. Apply. a b e l c j g f g h i k

WS9-15 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 6: Post Only the device_and_solder Group Post only the device_and_solder group and rotate to a view which shows the top device elements. a. Select Group b. Click on Post… c. Under Select Groups to Post select device_and_solder. d. Click Apply, then Cancel. e. Reset the Graphics by clicking on the following icon. f. Change the view by selecting Viewing. g. Click Named View Options… h. Select isometric_view for Select Named view. i. Close. j. Select the fit_view icon b a c d e h i f j

WS9-16 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 7: Apply Device Volumetric Heat Loads Apply device volumetric Heat loads a. Loads/BCs. b. Create/Heating/Element Uniform. c. Select Template, Volumetric Heat for Option. d. Under New Set Name enter R1. e. Under Target Element Type select 3D. f. Click on Input Data… g. Under Vol Heat Generation type 0.167E+09. h. Click OK. i. Click on Select Application Region… j. Click on FEM Filter. k. Under Select 3D Elements select only the top elements of R1 using shift-left mouse button. l. Click Add, OK, and Apply. m. Repeat for R2 through V4 using the data in Table 2. a b c d e g h j k l f i l Note: the heat load should be placed only on the top layer of elements, for the Silicon devices, NOT the Solder elements. m m k R1

WS9-17 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 7: Apply Device Volumetric Heat Loads Apply device volumetric heat loads a. Select Group. b. Click Post… c. Select hybrid_fem for Select Groups to Post. d. Click Apply then Cancel. e. Reduce the node size and reset the graphics by using the following icons on the main menu tool bar. c d g a b e Note: The continuous display of LBC markers, vectors and their values should have provided positive indication of the correct application of the LBCs. If you would like to further verify that the two fixed temperature, two heat transfer coefficient, and eight volumetric heating rate LBCs are correctly applied use the Show Tabular, Plot Contours, and Plot Markers action; they are selections in the Loads/BCs form. It may be desirable to use Group/Set Current for different groups to facilitate this LBCs check. e

WS9-18 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 8: Prepare and Run Analysis Prepare and submit the model for analysis. a. Analysis. b. Analyze/Full Model/ Full Run. c. Click on Solution Parameters… d. Click on Celsius for Calculation Temperature Scale. e. Select 1, Weakly Nonlinear Solution for Solver Option. f. OK. g. Click on Output Requests… h. Click on Celsius for Units Scale for Output Temperatures. i. OK. j. Apply. a b d e h i j c g f

WS9-19 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 9: Read and Plot Results Read results file and plot results. a. Under Analysis Applications Button, set to Read Result/Result Entities b. Click on Select Results File… c. Under the directories find the path that leads to microcircuit. d. Under Available Files select nr0.nrf.01 e. Click OK. f. Click on Select Rslt Template File… g. Under Files select pthermal_1_nodal.res_tmpl. h. OK. i. Apply. a b c e f g h i d Note: From within MSC.Patran the only indication that the analysis has successfully finished is the existence of an nr0.nrf.01 results file in a subdirectory one level below the working directory.

WS9-20 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Plot the results. a. Results. b. Create/Quick Plot. c. Under Select Result Cases select Time: D+00S… d. Under Select Fringe Result select Temperature. e. Select Fringe Attributes icon. f. Under Display select Element Edges. g. Click on Label Style… h. Under Label Format select Fixed. i. Use the slider bar to select 3 for Significant Figures. j. OK. k. Apply. Step 9: Read and Plot Results a b e f g h i j k c d

WS9-21 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation Step 10: Quit MSC.Patran Quit MSC.Patran. a. Select File. b. Click Quit from the drop down menu.

WS9-22 PAT312, Workshop 9, December 2006 Copyright 2007 MSC.Software Corporation