Deformation due to the Temperature Gradient #3 – Multiple Materialsexamples|products|Murata Software Co., Ltd.

Example3 Deformation due to the Temperature Gradient #3 – Multiple Materials

General

  • A heating chip is mounted on a substrate. The temperature gradient caused by the heating chip is calculated by thermal analysis [Watt]. This is the same as Exercise 10 of thermal analysis.
    Then, the deformation due to the temperature gradient is solved by Galileo (mechanical stress analysis).
     

  • The temperature gradient caused by the heating chip is calculated by Watt
    The result is forwarded to Galileo as a thermal load.
     

  • The deformation, the displacement and the mechanical stress are solved.
     

  • Unless specified in the list below, the default conditions will be applied.
     

 

Analysis Space

Item

Settings

Analysis Space

3D

Model unit

mm

 

Analysis Conditions

Select Thermal analysis and Mechanical stress analysis.

Item

Settings

Solvers

Thermal analysis [Watt]
Mechanical stress analysis [Galileo]

Thermal-Analysis Type

Steady-State Analysis

Options

N/A *

* “Thermal Load” is selected by default for the thermal load-mechanical stress coupled analysis.

 

The Step/Thermal Load tab is set as follows.

Tab

Setting Item

Settings

Step/Thermal Load *

Reference temperature

25[deg]

* The reached temperatures come from the thermal analysis.

Model

The same as Exercise 10 of thermal analysis.

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

SUB

006_Glass_epoxy *

1/Solid

GND

008_Cu *

2/Solid

MAINCHIP

001_Alumina *

3/Solid

SUBCHIP

001_Alumina *

4/Solid

HOLE

008_Cu *

5/Solid

HOLE

008_Cu *

6/Solid

HOLE

008_Cu *

7/Solid

HOLE

008_Cu *

8/Solid

HOLE

008_Cu *

9/Solid

HOLE

008_Cu *

10/Solid

HOLE

008_Cu *

11/Solid

HOLE

008_Cu *

* Available from the Material DB

 

The heat sources of MAINCHIP and SUBCHIP are set up as follows.

Body Attribute Name

Tab

Settings

MAINCHIP

Heat Source

0.2[W]

SUBCHIP

Heat Source

0.1[W]

Boundary Conditions

The heat transfer coefficient for the natural convection is set on the bottom face of GND as follows:

The radiation from the top and the sides is omitted.

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Settings

Bottom/Face

Thermal

Heat Transfer/Ambient Radiation

Natural convection*: 1.39[W/m2/deg5/4]

Room Temperature : 25[deg]

 

* The coefficient for the natural convection is calculated as follows. See [Heat Transfer/Ambient Radiation] for more information.

 

2.51×C×(1/L)^(1/4) = 1.39 [W/m2/deg5/4]

where

C = 0.26

Size of the substrate : 0.06×0.04

L (Typical Length) = (0.06 x 0.04 x 2) / (0.06 + 0.04) = 0.048

Results

The temperature distribution as a result of Watt is shown below.

 

The next figure shows the vectors of displacement as a result of Galileo following Watt.

The substrate corners which shows the low temperature are bent downward.