Two Resistor Component

Analysis > Boundary Conditions > Two-Resistor component

Introduction

A two-resistor component is an ElectroFlo smart object used for compact thermal modelling (CTM) of electronic components.

Description

  1. Electronic components may be modelled in ElectroFlo using detailed thermal modelling (DTM) or compact thermal modelling (CTM).
  2. A CTM is a reduced-order, mixed fidelity thermal model of a component that uses nodes and resistors to define the component’s thermal behavior.

  3. The two-resistor (2R) component is the simplest and most widely used CTM. The thermal resistance values for the two resistors are package dependent and provided by most manufacturers.

  4. ElectroFlo provides the ability two define 2R components utilizing component footprint (block option) or utilizing the correct component geometry.
  5. To select the component “body”, the user must click on the “Select Bodies” panel and include regions to define the component body. The mouse selection will automatically switch to Body pick mode.
  6. Component heat dissipation must be entered in “Total heat dissipation” box. This heat will be applied to the bodies and the entire selection of bodies is represented by a single thermal node (junction node).
  7. To select the component “case surface”, the user must click on the “Select faces” in the “junction to case” panel and include faces to define the component case. The mouse selection will automatically switch to face pick mode.
  8. Junction to case thermal resistance will be applied between the body node and neighboring elements to case faces.
  9. To select the component “board surface”, the user must click on the “Select faces” in the “junction to board” panel and include faces to define the component board contact area. The mouse selection will automatically switch to face pick mode.
  10. Junction to board thermal resistance will be applied between the body node and neighboring elements to board faces.
  11. Remaining external faces of the component will be assumed insulated.
  12. Total heat dissipation can be either constant or variable if a multiplier function is defined when creating the two-resistor component.

  13. There are three types of multiplier tables:
    1. Time - Multiplier value varies as a function of time.
    2. Iteration - Multiplier value varies as a function of the iteration.
    3. Sensor – Multiplier value varies based on the selected sensor output.
    4. Thermostat - Multiplier value varies based on the ON/OFF status of the selected thermostat.

Review and Plotting

User can review all the defined 2R components in the solution using right click on “Review 2R Component” under “Smart Objects” in solution browser. If the Solution is finished, user can review the Temperatures at case, board and junction of resistor component.

Temperature at case, board and junction of resistor component can be plotted by right click on “Resistor Component” under “Smart Objects” in solution browser.

Importing and Exporting

Model setup time can be significantly reduced by using the option “Import 2R Components”. This option can be found in the Solution Browser after right-clicking in “Smart Objects”.

Users can export existing 2R components as a CSV file by right-clicking in “Smart Objects” within the Solution Browser and selecting “Export 2R components”.

A CSV file can be selected for importing 2R components, and the format should be the one shown below:

Component names in the model should coincide with the names in the column “Part Name” to successfully import and create the 2R components.