The trend of miniaturization and intgration of the electronic device has put forward higher requirements on efficiency of heat radiating, which can hardly be satisfied by the traditional forced convection heat dissipation method. In this paper, the strategy of topology optimization technique is adopted to greatly improve the heat dissipation efficiency of a semiconductor ignition device. The penalization method is used to implement the topology optimization process. Three kinds of objective functions of thermal compliance, temperature variance and geometric average temperature were separately applied in the topological optimization of two typical uniform heat generation cases, and the resulted topologically optimization results were analyzed and compared. Based on the two benchmark cases, the appropriate objective function was selected to conduct structural optimization of semiconductor bridge ignition devices with the aim of making the highest temperature in the design domain the lowest possible. Additionally, a parametric study on the effect of thermal conductivity on topology optimization results was conducted, which leads to a design suggestion beneficial for heat dissipation and material selection.