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Thermal Analysis                                                            335



                                                         All dimensions are in millimeters.


                           Die thickness = 2 mm
                         Substrate thickness = 2 mm
                                                                               40.000
                                                                            20.000
                                 Copper die


                                                                20.000
                    Silicon substrate
                                                               40.000


              9.10 The following square platform with two arms has a thickness of 1 mm and is
                 made of silicon with a thermal conductivity  k = 130 W/(m°C),  Young’s  modu-
                 lus  E = 200 GPa,  Poisson’s  ratio  ν = 0.27, and thermal expansion coefficient
                           −6
                 α = 2.6 × 10 /°C. Ignore the effects of convective heat transfer. (1) Determine the
                 temperature distribution in the platform when the temperatures of the upper
                 and lower ends are set uniform at 40°C and 20°C, respectively, as shown below.
                 (2) Suppose the ends of the two arms are fixed. Determine the thermally induced
                 deformation and stresses in the platform.


                   T upper  = 40°C                      All dimensions are in centimeters.

                                                  1.000     12.000
                                                                     1.000     1.000



                                                                              10.000




                                                       1.000
                                                               1.000

                                                                    10.000
                                                                   12.000      1.000
                                        T lower  = 20°C
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