Table 2 Specific thermal resistances and thermal capacitances per unit area, illustrating that the decreased chip thickness from 350 to 110 μm has a minimal beneficial impact on the specific thermal resistance, whereas the adverse decrease of the thermal capacitance per unit area is proportional to the decreased chip thickness.
Chip thickness (μm) | Components of specific thermal resistance,\({{\varvec{R}}}_{{\varvec{s}}{\varvec{p}}-{\varvec{t}}{\varvec{h}}}\) | Total \({{\varvec{R}}}_{{\varvec{s}}{\varvec{p}}-{\varvec{t}}{\varvec{h}}}\) (\({^\circ \mathrm{C}\, \mathbf{m}\mathbf{m}}^{2}/\mathbf{W}\)) |
|---|---|---|
110 | \({R}_{sp-th (a)}=\frac{{t}_{SiC (a)}}{{k}_{SiC}}+\frac{{t}_{solder}}{{k}_{solder}}+\frac{{t}_{Cu}}{{k}_{Cu}}=0.22+0.83+2.03\) | 3.1 |
350 | \({R}_{sp-th (b)}=\frac{{t}_{SiC (b)}}{{k}_{SiC}}+\frac{{t}_{solder}}{{k}_{solder}}+\frac{{t}_{Cu}}{{k}_{Cu}}=0.71+0.83+2.03\) | 3.6 |
Chip thickness (μm) | Thermal capacitance per unit area,\({C{\prime}}_{th}\) | Total \({C{\prime}}_{th}\) (\(\mathrm{J}/^\circ \mathrm{C}\, {\mathrm{m}}^{2}\)) |
|---|---|---|
110 | \({{C}{\prime}}_{th \left(a\right)}= {\rho }_{SiC}{c}_{SiC}{t}_{SiC \left(a\right)}=3210\times 700\times 110\times {10}^{-6}\) | \(247.2\) |
350 | \({C{\prime}}_{th (b)}= {\rho }_{SiC}{c}_{SiC}{t}_{SiC (b)}=3210\times 700\times 350\times {10}^{-6}\) | \(786.45\) |
