Our initial thermal study has provided preliminary results for glass and silicon interposers. Both glass and silicon have their advantages and disadvantages. The glass interposer provides good insulation but lower heat dissipation, while the silicon interposer has better heat dissipation. These results are extremely useful for the reliability of the 3D packaging systems. Concerning the glass interposer fabrication, we have used two laser drilling methods, the first one using Excimer laser and the second using the UV laser. The results obtained are both interesting and provide the required targets both in dimensions and form.