Solid Mechanics
In the Physics toolbar, click Electrostatics (es)  (not the upper part where this icon shows but the lower part where the text “Electrostatics” shows with a downward facing black triangle icon) and choose Solid Mechanics (solid) .
Thermal Expansion 1
1
In the Model Builder window, expand Solid Mechanics (solid) , and then click Linear Elastic Material 1 . In the Physics toolbar click Attributes and choose Thermal Expansion .
The model temperature should be set to the previously defined room temperature parameter, T0.
2
In the Settings window for Thermal Expansion locate the Model Inputs section to choose the “User defined” option for the Temperature list. In the T text field, enter T0.
The reference temperature indicates the temperature at which the structure had no thermal strains. In this case, we set it to the previously defined parameter, Tref. Tref represents the temperature at which the silicon die was bonded to the metal carrier plate.
3
Choose the “User defined” option for the Volume reference temperature list. In the Tref text field, enter Tref.