Through-Silicon via Submount for Flip-Chip LEDs

A blue light emitting diode (LED) was prepared by a flip-chip (FC) LED and three-dimensional through-silicon via (3D-TSV) technique. The experimental results indicated that the diameter and length of the Si via were about 180 μm and 400 μm, respectively. The Cu was uniformly and high density filled in each TSV, and the average resistance was about 0.14 m. It was also found that the 96.43Sn-3.57at%Ag bumps were electroplated on the Cu plugged TSVs of a silicon substrate, and these were smoother at 250^◦C. After reflow, a 3D blue light emitting diode was prepared by peak bonding at 250^◦C and 1000 N pressure for 30 min. Compared with the output of the LED 417.17 mw/w, that of the 3D LED was 424.67 mw/w.