PCB Thermal Analysis using Ansys-Icepak

Objective :

The main objective of this challenge is to learn the concepts of the PCB modeling and also the

1. How to import trace layout of a typical PCB and solve two sample cases based on the trace layout information.
2. How to use Model layers separately option for better accuracy.
3. how to model resistive heating or Joule heating of the imported traces in the PCB.
4. Understand the varying orthotropic conductivity on the board using a profile mesh size.
5. A detailed conductivity map of the PCB.

1. Introduction:

A printed circuit board (PCB) mechanically supports and electrically connects electrical or electronic component electrical or electronic components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.

Printed circuit boards are used in all but the simplest electronic products. They are also used in some electrical products, such as passive switch boxes.

Alternatives to PCBs include wire wrap and point to point construction, both once popular but now rarely used. PCBs require additional design effort to lay out the circuit, but manufacturing and assembly can be automated. Electronic computer-aided design software is available to do much of the work of layout. Mass-producing circuits with PCBs is cheaper and faster than with other wiring methods, as components are mounted and wired in one operation. Large numbers of PCBs can be fabricated at the same time, and the layout only has to be done once. PCBs can also be made manually in small quantities, with reduced benefits.

PCBs can be single-sided one copper layer, double-sided two copper layers on both sides of one substrate layer, or multi-layer outer and inner layers of copper, alternating with layers of the substrate. Multi-layer PCBs allow for much higher component density because circuit traces on the inner layers would otherwise take up surface space between components. The rise in popularity of multilayer PCBs with more than two, and especially with more than four, copper planes was concurrent with the adoption of surface mount technology. However, multilayer PCBs make repair, analysis, and field modification of circuits much more difficult and usually impractical.

2. Problem Description:

A PCB board, library files, and traces are imported to create the model. The model is first solved for conduction only, without the components and then solved using the actual components with forced convection.

• Modeling: Files are provided with this

1. Create a new project
2. Import board layout *.bdf & *.ldf (The board and the associated library files have to be chosen at this step and the trace file can be imported later.)
3. Form the nonconformal assembly
4. Import ECAD file (*.anf) A1.anf can be found in the folder containing the input files downloaded for his tutorial.
5. Once the import process is completed, you can edit the layer information in the Board layer and via information panel (metal layers are pure Cu and the dielectric layers are FR-4.)
6. Enter the layer thickness as shown in the table below.

Layer No.	Layer Thickness (mm)
1	0.04
2	0.45364
3	0.062
4	0.467
5	0.055
6	0.442
7	0.045

7. Specify Grid density by size (0.508 mm X 0.508 mm)

Conduction only model:

Thermal conduction is the transfer of internal energy by microscopic collisions of particles and the movement of electrons within a body. The colliding particles, which include molecules, atoms, and electrons, transfer disorganized microscopic kinetic and potential energy, jointly known as internal energy. Conduction takes place in all phases solid, liquid, and gas. The rate at which energy is conducted as the heat between two bodies depends on the temperature difference and hence temperature gradient between the two bodies and the properties of the conductive interface through which the heat is transferred.

Heat spontaneously flows from a hotter to a colder body. For example, heat is conducted from the hotplate of an electric stove to the bottom of a saucepan in contact with it. In the absence of an opposing external driving energy source, within a body or between bodies, temperature differences decay over time, and thermal equilibrium is approached, temperature becoming more uniform

In conduction, the heat flow is within and through the body itself. In contrast, in heat transfer by Thermal radiation, the transfer is often between bodies, which may be separated spatially. Also possible is the transfer of heat by a combination of conduction and thermal radiation. In convection, the internal energy is carried between bodies by a moving material carrier. In solids, conduction is mediated by the combination of vibrations and collisions of molecules, of propagation and collisions of phonons, and diffusion and collisions of free electrons. In gases and liquids, conduction is due to the collisions and diffusion of molecules during their random motion. Photons in this context do not collide with one another, and so heat transport by electromagnetic radiation is conceptually distinct from heat conduction by microscopic diffusion and collisions of material particles and phonons. But the distinction is often not easily observed unless the material is semi-transparent.

3. Meshing & BC setting:

1.consider aboard without any components. Make all objects (including the openings) inactive except the BOARD_OUTLINE.1 object.

The circuit board has been considered without any components in the domain to see the analysis on the board domain.

2. Select the cabinet and select Autoscale from the Edit window to make the size of the board and the cabinet the same.

We have used an auto-scale option for making the size of the board and cabinet at the same.

3.Min z: Temperature from the External conditions drop-down list, and keep the ambient temperature (20°C).

We have considered the external conditions on the cabinet as shown above and the considered ambient temperature on the min z wall side is 20°C.

4.Max z: specify a Heat flux of 20000 W/m2 in the Thermal specification

We have considered the external conditions on the cabinet as shown above and the considered heat flux is 20000 W/m^2.

5. The rest of the sides are insulated. The board will be simulated using a conduction-only model.

The remaining walls were considered as the insulated in the x and y directions and the z-direction, we have used the conduction model.

6. Generate mesh. Specify a Max element size for X, Y, and Z as 2.032, 2.032, and 0.05 mm respectively, and a Minimum gap for X, Y, and Z as 1, 1, and 0.01 mm respectively.

Mesh generation is the practice of creating a mesh, a subdivision of a continuous geometric space into discrete geometric and topological cells. Often these cells form a simplicial complex. Usually, the cells partition the geometric input domain. Mesh cells are used as discrete local approximations of the larger domain. Meshes are created by computer algorithms, often with human guidance through a GUI, depending on the complexity of the domain and the type of mesh desired. The goal is to create a mesh that accurately captures the input domain geometry, with high-quality (well-shaped) cells, and without so many cells to make subsequent calculations intractable. The mesh should also be fine (have small elements) in areas that are important for the subsequent calculations

Mesh generation

Meshes are used for rendering to a computer screen and for physical simulation such as finite element analysis or computational fluid dynamics. Meshes are composed of simple cells like triangles because, e.g., we know how to perform operations such as finite element calculations (engineering) or ray tracing (computer graphics) on triangles, but we do not know how to perform these operations directly on complicated spaces and shapes such as a roadway bridge. We can simulate the strength of the bridge, or draw it on a computer screen, by performing calculations on each triangle and calculating the interactions between triangles.

4. Numerical setting:

Basic parameters: Flow & Radiation is off

In the Basic parameters, we have considered the flow, and radiation was turned off and the flow region was considered to be laminar.

Set no of iterations 500 and convergence criteria for energy to 1e-12

The total number of iteration was set to be 500 iterations and coming to the convergence criteria the flow was set to 0.000001 and energy was 1e-12, and the turbulent kinetic energy and turbulent dissipation rate were 0.001

From the residual plot, it is clear that the simulation has reached the converged stage and also obtained the converge, and they are no fluctuations in the plot.

Temperature Linear solver: F cycle is selected for Type Enter 1e-6 for both the Termination criterion and Residual reduction tolerance

In applied mathematics, discretization is the process of transferring continuous functions, models, variables, and equations into discrete counterparts. This process is usually carried out as a first step toward making them suitable for numerical evaluation and implementation on digital computers.

The discretization scheme properties were set accordingly as shown below

Enter a value of 1e-6 for both the Termination criterion and Residual reduction tolerance and the F cycle is was selected.

Select Double for the solver Precision.

Single precision means that the floating-point numbers will be represented in a 32-bit system whereas double-precision means that they will be represented in a 64-bit system. So Calculation in double precision will be more accurate.

Save the model:

ANSYS Icepak will save the model for you automatically before it starts the calculation, but it is a good idea to save the model (including the mesh) as well. If we exit ANSYS Icepak before you start the calculation, we will be able to open the job that we saved and continue with our analysis. If we start the calculation in the current ANSYS Icepak session, ANSYS Icepak will simply overwrite your job file when it saves the model.

Solve the model.

There are no universal metrics for judging convergence, a good indicator is when the solution no longer changes with more iterations, and when the residuals have decreased to a certain degree. The default criterion is that each residual will be reduced to a value of less than 10^-3 except the energy residual, for which the default criterion is 10^-7. It is a good idea to judge convergence not only by examining residuals levels but also by monitoring relevant integrated quantities.

ANSYS Icepak will begin to calculate a solution for the model, and a separate window will open where the solver will print the numerical values of the residuals. ANSYS Icepak will also open the Solution residuals graphics display and control window, where it will display the convergence history for the calculation.

5. Examine and post-process the results:

View the traces in three different ways, i.e. single color, color by layer, or color by trace

All traces found on external PCB layers as opposed to internal layers must be protected from the elements. If left unprotected, the copper will oxidize and deteriorate, making the circuit board unusable. An obvious visual sign of corroded copper is its color it will be green. One famous example of copper oxidation is the Statue of Liberty. PCB copper plating—also known as copper coating, copper finish, and the surface finish has two essential functions:

1. To protect the exposed copper circuitry

2. To provide a solderable surface when assembling soldering components to the PCB. A variety of PCB copper plating options exist, and each carries its advantages and disadvantages.

single color

A single color for the trace image was shown above.

the color by layer

Color by layer for the trace image was shown above.

color by trace

Color by trace for the trace layout image was shown above.

View the fraction of metal traces based on the grid density

There have been a lot of improvements and advancements in printed circuit board technology. From manufacturing a PCB to deciding its board density, PCBs have seen a lot of developments, but the one thing that remains unchanged is the basic construction of a PCB. A printed circuit board can have a single layer, or it may vary from 1 to 20 layers depending upon the application for which it is designed. Twisted Traces is a leading manufacturer of PCBs, which provides PCBs in 1-20 layers (FR- 4, FR- 406, 370 HR), and in 1- 2 Layers (Rogers, Aluminum/Copper Base, Teflon). There are two main layers on any PCB. They are as follows:

1. Inner Layers
   Also referred to as internal layers in multilayer PCBs, the inner layers can be fabricated with a positive or negative polarity. Sometimes, inner layers employ the copper pour technique, which helps a lot in the layer-to-layer bonding process. The copper pour helps reduce the etchant during the PCB manufacturing process. The copper weight and thickness are customizable and depend on the application requirements. The weight of copper in the layer determines the minimum trace width and spacing that can be manufactured.
2. Outer Layers
   Outer layers are also known as an external copper layer of a printed circuit board. These layers are used to attach electronic components either by surface mounting technique or soldering into the through-holes. The outer layer consists of a copper foil, which is electroplated with copper. This is done to increase the thickness and add copper to the through-hole barrels. The thickness of the finished copper is customizable depending upon the application requirements.

Metal traces base layer-1

The metal traces for the layer-1 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-2

The metal traces for the layer-2 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-3

The metal traces for the layer-3 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-4

The metal traces for the layer-4 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-5

The metal traces for the layer-5 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-6

The metal traces for the layer-6 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-7

The metal traces for the layer-7 was shown above and the representation of the legend shown the amount of the metal trace on the board.

The plane cut Point and normal. Make sure that PX, PY, PZ are 0, 0, and 0.78232, respectively, and NX, NY, and NZ are 0, 0, and 1, respectively.

The cut plane was generated concerning the required plane and the cut plane was considered according to the point of normal and the respective dimension was considered in the plane.

Temperature contour

The mid-plane temperature distribution shows that the high-temperature regions occur at the no-trace areas where the opposite is true for the low-temperature regions, i.e. maximum trace concentration leads to low temperatures. This is expected as the copper content is directly proportional to the trace concentration. It is worth noting that if a compact or detailed PCB were used instead of the traced PCB, one would obtain a fixed temperature for the entire mid-plane and this fixed temperature would be different from the average temperature of the traced PCB on the same plane.

The initial temperature was at a temperature of 20°C and the final temperature has reached a maximum temperature of 108°C

The animation for the temperature profile on the PCB board.

animation for the temperature profile on the PCB

K_Z contour

The spatially varying non-uniform conductivity of the board can also be viewed during post-processing. The conductivities in the three directions K_X, K_Y, and K_Z are available as post-processing variables with plane cuts and object faces. The above plots K-z at the board midplane. In the present case, since we chose not to model the layers separately there will be no variation of the conductivities in the board-normal direction.

we can see the thermal conductivity was initial at 5 W-m/k and has reached a final temperature of 60W-m/k.

Force convection model:

Forced convection is a mechanism or type of transport in which fluid motion is generated by an external source like a pump, fan, suction device, etc. Alongside natural convection, thermal radiation, and thermal conduction it is one of the methods of heat transfer and allows significant amounts of heat energy to be transported very efficiently.

3. Meshing & BC setting:

Put the actual components back into the model.

The components were kept back into geometry which is important to the analysis for the prediction of the temperature that has been obtained in the domain.

Highlight the two wall objects created for the “conduction only" model and drag them into the Inactive folder. Click on the Cabinet and Autoscale it from the Edit window.

We have used an auto-scale option for making the size of the board and cabinet at the same.

The remaining walls were considered as openings in the X direction and insulated in the y directions and the z-direction, we have used the conduction model.

Assign an X Velocity of -1.5 m/s for Max x side of the cabinet.

We have assigned a value of -1.5m/sec in the x-direction of the opening which has been provided in the cabinet facing.

Generate mesh. Specify a Max element size for X, Y, Z as 9,5, 7, and 0.7 mm respectively.

Mesh generation is the practice of creating a mesh, a subdivision of a continuous geometric space into discrete geometric and topological cells. Often these cells form a simplicial complex. Usually, the cells partition the geometric input domain. Mesh cells are used as discrete local approximations of the larger domain. Meshes are created by computer algorithms, often with human guidance through a GUI, depending on the complexity of the domain and the type of mesh desired. The goal is to create a mesh that accurately captures the input domain geometry, with high-quality (well-shaped) cells, and without so many cells to make subsequent calculations intractable. The mesh should also be fine (have small elements) in areas that are important for the subsequent calculations

Meshes are used for rendering to a computer screen and for physical simulation such as finite element analysis or computational fluid dynamics. Meshes are composed of simple cells like triangles because, e.g., we know how to perform operations such as finite element calculations (engineering) or ray tracing (computer graphics) on triangles, but we do not know how to perform these operations directly on complicated spaces and shapes such as a roadway bridge.

Mesh generation:

We can simulate the strength of the bridge, or draw it on a computer screen, by performing calculations on each triangle and calculating the interactions between triangles.

4. Numerical setting:

Basic parameters toggle on the Flow button. Keep and choose Turbulent and Zero equation for the flow regime

In the Basic parameters, we have considered the flow, and radiation was turned on and the flow region was considered to be Turbulent.

set no of iterations 500 and convergence criteria for energy to 1e-12

The total number of iteration was set to be 500 iterations and coming to the convergence criteria the flow was set to 0.00001 and energy was 1e-12, and the turbulent kinetic energy and turbulent dissipation rate were 0.001

From the residual plot, it is clear that the simulation has reached the converged stage and also obtained the converge, and they are no fluctuations in the plot.

Temperature Linear solver: F cycle is selected for Type Enter 1e-6 for both the Termination criterion and Residual reduction tolerance

In applied mathematics, discretization is the process of transferring continuous functions, models, variables, and equations into discrete counterparts. This process is usually carried out as a first step toward making them suitable for numerical evaluation and implementation on digital computers.

The discretization scheme properties were set accordingly as shown below

Enter a value of 1e-6 for both the Termination criterion and Residual reduction tolerance and the F cycle is was selected.

Select Double for the solver Precision.

Single precision means that the floating-point numbers will be represented in a 32-bit system whereas double-precision means that they will be represented in a 64-bit system. So Calculation in double precision will be more accurate.

Save the model.

ANSYS Icepak will save the model for you automatically before it starts the calculation, but it is a good idea to save the model (including the mesh) as well. If we exit ANSYS Icepak before you start the calculation, we will be able to open the job that we saved and continue with our analysis. If we start the calculation in the current ANSYS Icepak session, ANSYS Icepak will simply overwrite your job file when it saves the model.

Enable Sequential solution of flow and energy equations

The sequential solution of flow and energy equation was enabled for the simulation

Solve the model.

There are no universal metrics for judging convergence, a good indicator is when the solution no longer changes with more iterations, and when the residuals have decreased to a certain degree. The default criterion is that each residual will be reduced to a value of less than 10^-3 except the energy residual, for which the default criterion is 10^-7. It is a good idea to judge convergence not only by examining residuals levels but also by monitoring relevant integrated quantities.

ANSYS Icepak will begin to calculate a solution for the model, and a separate window will open where the solver will print the numerical values of the residuals. ANSYS Icepak will also open the Solution residuals graphics display and control window, where it will display the convergence history for the calculation.

5. Examine and post-process the results:

View the traces in three different ways, i.e. single color, color by layer, or color by trace

All traces found on external PCB layers as opposed to internal layers must be protected from the elements. If left unprotected, the copper will oxidize and deteriorate, making the circuit board unusable. An obvious visual sign of corroded copper is its color it will be green. One famous example of copper oxidation is the Statue of Liberty. PCB copper plating—also known as copper coating, copper finish, and the surface finish has two essential functions:

1. To protect the exposed copper circuitry

2. To provide a solderable surface when assembling soldering components to the PCB. A variety of PCB copper plating options exist, and each carries its advantages and disadvantages.

single color

A single color for the trace image was shown above.

The color by layer

Color by layer for the trace image was shown above.

color by trace

Color by trace for the trace layout image was shown above.

View the fraction of metal traces based on the grid density

There have been a lot of improvements and advancements in printed circuit board technology. From manufacturing a PCB to deciding its board density, PCBs have seen a lot of developments, but the one thing that remains unchanged is the basic construction of a PCB. A printed circuit board can have a single layer, or it may vary from 1 to 20 layers depending upon the application for which it is designed. Twisted Traces is a leading manufacturer of PCBs, which provides PCBs in 1-20 layers (FR- 4, FR- 406, 370 HR), and in 1- 2 Layers (Rogers, Aluminum/Copper Base, Teflon). There are two main layers on any PCB. They are as follows:

1. Inner Layers
   Also referred to as internal layers in multilayer PCBs, the inner layers can be fabricated with a positive or negative polarity. Sometimes, inner layers employ the copper pour technique, which helps a lot in the layer-to-layer bonding process. The copper pour helps reduce the etchant during the PCB manufacturing process. The copper weight and thickness are customizable and depend on the application requirements. The weight of copper in the layer determines the minimum trace width and spacing that can be manufactured.
2. Outer Layers
   Outer layers are also known as an external copper layer of a printed circuit board. These layers are used to attach electronic components either by surface mounting technique or soldering into the through-holes. The outer layer consists of a copper foil, which is electroplated with copper. This is done to increase the thickness and add copper to the through-hole barrels. The thickness of the finished copper is customizable depending upon the application requirements.

Metal traces base layer-1

The metal traces for the layer-1 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-2

The metal traces for the layer-2 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-3

The metal traces for the layer-3 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-4

The metal traces for the layer-4 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-5

The metal traces for the layer-5 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-6

The metal traces for the layer-6 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-7

The metal traces for the layer-7 was shown above and the representation of the legend shown the amount of the metal trace on the board.

The plane cut Point and normal. Make sure that PX, PY, PZ are 0, 0, and 0.78232, respectively, and NX, NY, and NZ are 0, 0, and 1, respectively.

The cut plane was generated concerning the required plane and the cut plane was considered according to the point of normal and the respective dimension was considered in the plane.

Temperature contour

The temperature distribution at the top of the surface of the board was shown above. Two hot spots are identified underneath the high heat flux components. and the initial temperature was at 13.3°C and the maximum temperature has reached a temperature of 106.7°C

Animation for the temperature contour on the PCB

The temperature distribution profile on the PCB

K_Z contour:

The spatially varying non-uniform conductivity of the board can also be viewed during post-processing. The conductivities in the three directions K_X, K_Y, and K_Z are available as post-processing variables with plane cuts and object faces. The above plots K-z at the board midplane. In the present case, since we chose not to model the layers separately there will be no variation of the conductivities in the board-normal direction.

we can see the thermal conductivity was initial at 25W-m/k and has reached a final temperature of 200W-m/k.

6. Joule/Trace Heating

Since PCB traces have electrical resistance, they heat up as current flows through them. Modeling this phenomenon will provide us with an accurate prediction of the temperature distribution in the PCB, which can be important, for example, in evaluating the performance of the cooling system. The model in the tutorial contains imported traces and will be used in this tutorial. You will determine the Joule/trace heating capacity of the traces.

a. Build the Model Edit the Board outline of the previous model to open the model trace heating panel and select INT1_3 layer filter the trace to view by setting Min Area in the Display traces filter group box use a Min Area of 4124 mm2

We have created a min area of the traces filter group Box used a min area of 4124 mm2

b. Before you create a solid trace of trace A3V3_2261 set the Max angle filter to 135 and the Min length filter to 1.0 m to ignore the fine details in the trace geometry and reduce the mesh count.

The trace A3V3_2261 set the Max angle filter to 135 and the Min length filter to 1.0 m to ignore the fine details in the trace geometry and reduce the mesh count.

c. Create a solid polygonal solid block for trace A3V3_2261

Created a solid block for the trace as shown above A3V3_2261

d. Select the polygonal trace just created from the Model manager window Under Thermal specification next to Joule heating, click Edit to open the Joule heating power panel. Set Resistivity, temperature coefficient (C), and reference temperature (Tref)

The resistivity was set to 1.72e-008 and the temperature coefficient was set to 0.0039 and the reference temperature was set to 20 as shown above.

e. One source is for the current source (source.1) and the other for the voltage source (source.2). Both sources are created on the same layer as the layer of the wire. The area of each
source in the area to apply the voltage or the current. • The recommendation of the source objects pair for joule heating is the current-voltage pair or voltage- voltage pair.

The recommendation of the source objects pair for joule heating is the current-voltage pair or voltage- voltage pair as shown above in the picture.

Meshing & BC setting:

a. Create a non-conformal assembly for the trace. Since we are performing a joule heating calculation, it is necessary to have a high or medium-mesh quality in case the joule heating calculation diverges. To create a high-quality mesh, we will create an assembly with the 3D trace geometry and set a small element size.

we have created an assembly with the 3D trace geometry and set a small element size.

b. Ensure the Mesh type is Mesher-HD.

We have used the Mesher-MD for the mesh type

c. Generate mesh. Specify a Max element size for X, Y, Z as 9.5, 7, and 0.75 mm respectively.

The max element size was set accordingly as shown in the figure above.

d. assign an X Velocity of -1.5 m/s for Max x side of the cabinet

The X Velocity of -1.5 m/s for Max x side of the cabinet

Numerical setting:

f. Basic parameters toggle on the Flow button. Keep and choose the Turbulent and Zero the equation for the flow regime

Basic settings were set according to as shown in the above picture

g. set no of iterations 500 and convergence criteria for energy to 1e-8 and Flow is 1e-4

The iterations were set accordingly as shown in the figure above.

From the residual plot, it is clear that the simulation has reached the converged stage and also obtained the converge, and they are no fluctuations in the plot.

h. Temperature Linear solver: F cycle is selected for Type Enter 1e-6 for both the Termination criterion and Residual reduction tolerance

The f type cycle was used and the terminational criterion and residual reduction tolerance was set to 1e-6

i. Ensure that BCGSTAB is chosen as the Stabilization criterion for both Temperature and Joule Heating Potential.

The stabilization criterion for both temperature and joule heating potential was set to BCGSTAB

j. Select Double for the solver Precision.

Single precision means that the floating-point numbers will be represented in a 32-bit system whereas double-precision means that they will be represented in a 64-bit system. So Calculation in double precision will be more accurate.

k. Save the model.

ANSYS Icepak will save the model for you automatically before it starts the calculation, but it is a good idea to save the model (including the mesh) as well. If we exit ANSYS Icepak before you start the calculation, we will be able to open the job that we saved and continue with our analysis. If we start the calculation in the current ANSYS Icepak session, ANSYS Icepak will simply overwrite your job file when it saves the model.

l. Enable Sequential solution of flow and energy equations

m. Solve the model.

There are no universal metrics for judging convergence, a good indicator is when the solution no longer changes with more iterations, and when the residuals have decreased to a certain degree. The default criterion is that each residual will be reduced to a value of less than 10^-3 except the energy residual, for which the default criterion is 10^-7. It is a good idea to judge convergence not only by examining residuals levels but also by monitoring relevant integrated quantities.

ANSYS Icepak will begin to calculate a solution for the model, and a separate window will open where the solver will print the numerical values of the residuals. ANSYS Icepak will also open the Solution residuals graphics display and control window, where it will display the convergence history for the calculation.

Examine and post-process the results:

n. view the traces in three different ways, i.e. single color, color by layer, or color by trace

All traces found on external PCB layers as opposed to internal layers must be protected from the elements. If left unprotected, the copper will oxidize and deteriorate, making the circuit board unusable. An obvious visual sign of corroded copper is its color it will be green. One famous example of copper oxidation is the Statue of Liberty. PCB copper plating—also known as copper coating, copper finish, and the surface finish has two essential functions:

1. To protect the exposed copper circuitry

2. To provide a solderable surface when assembling soldering components to the PCB. A variety of PCB copper plating options exist, and each carries its advantages and disadvantages.

single color

A single color for the trace image was shown above.

color by layer

Color by layer for the trace image was shown above.

color by trace

Color by trace for the trace layout image was shown above.

o. View the fraction of metal traces based on the grid density

There have been a lot of improvements and advancements in printed circuit board technology. From manufacturing a PCB to deciding its board density, PCBs have seen a lot of developments, but the one thing that remains unchanged is the basic construction of a PCB. A printed circuit board can have a single layer, or it may vary from 1 to 20 layers depending upon the application for which it is designed. Twisted Traces is a leading manufacturer of PCBs, which provides PCBs in 1-20 layers (FR- 4, FR- 406, 370 HR), and in 1- 2 Layers (Rogers, Aluminum/Copper Base, Teflon). There are two main layers on any PCB. They are as follows:

1. Inner Layers
   Also referred to as internal layers in multilayer PCBs, the inner layers can be fabricated with a positive or negative polarity. Sometimes, inner layers employ the copper pour technique, which helps a lot in the layer-to-layer bonding process. The copper pour helps reduce the etchant during the PCB manufacturing process. The copper weight and thickness are customizable and depend on the application requirements. The weight of copper in the layer determines the minimum trace width and spacing that can be manufactured.
2. Outer Layers
   Outer layers are also known as an external copper layer of a printed circuit board. These layers are used to attach electronic components either by surface mounting technique or soldering into the through-holes. The outer layer consists of a copper foil, which is electroplated with copper. This is done to increase the thickness and add copper to the through-hole barrels. The thickness of the finished copper is customizable depending upon the application requirements.

Metal traces base layer-1

The metal traces for the layer-1 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-2

The metal traces for the layer-2 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-3

The metal traces for the layer-3 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-4

The metal traces for the layer-4 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-5

The metal traces for the layer-5 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-6

The metal traces for the layer-6 was shown above and the representation of the legend shown the amount of the metal trace on the board.

Metal traces base layer-7

The metal traces for the layer-7 was shown above and the representation of the legend shown the amount of the metal trace on the board.

p. The plane cut Point and normal. Make sure that PX, PY, PZ are 0, 0, and 0.78232, respectively, and the NX, NY, and NZ are 0, 0, and 1, respectively.

The cut plane was generated concerning the required plane and the cut plane was considered according to the point of normal and the respective dimension was considered in the plane.

q. Temperature contour on trace layer

The temperature distribution at the top of the surface of the board was shown above. Two hot spots are identified underneath the high heat flux components. and the initial temperature was at 20°C and the maximum temperature has reached a temperature of 60°C

r. K_Z

The Model layers separately option automatically creates contact resistance plates in the plane of the board at the start and end locations of each metal layer. These dummy plates have zero thermal resistance and their sole purpose is to ensure proper mesh resolution within the board. shows the plates created for the tracing layers on this board.

The spatially varying non-uniform conductivity of the board can also be viewed during post-processing. The conductivities in the three directions K_X, K_Y, and K_Z are available as post-processing variables with plane cuts and object faces. The above plots K-z at the board midplane. In the present case, since we chose not to model the layers separately there will be no variation of the conductivities in the board-normal direction.

we can see the thermal conductivity was initial at 13 W-m/k and has reached a final temperature of 110 W-m/k.

Conclusion:

We have performed a detailed analysis of the PCB circuit board, trace layout, and also calculated the different values of the temperature and thermal conductivity on the required domain.