Materials
The user-defined properties added previously for silicon did not include its thermal expansivity, so this must be added.
Silicon
COMSOL Multiphysics shows a warning in the material properties settings to indicate a missing property.
1
In the Model Builder window, under Component 1 (comp1) > Materials
click Silicon
.
2
In the Settings window for Material locate the Material Contents section.
3
In the table, add a value for the thermal expansion coefficient of silicon to the appropriate row:
Property
Name
Value
Coefficient of thermal expansion
alpha…
2.6e-6
click Silicon 
.