| 摘要 |
PURPOSE: To perform interconnection while preventing the concentration of currents and decreasing the leaked currents of a thin film by providing spherical projections having a maximum height around a interconnection area. CONSTITUTION: An Si substrate 1 is covered with a protective layer 3 of SiO2 or Si3 N4 , etc., except for a pad 2, and a window 12 smaller than the pad 2 is prepared. Resist masking 5 is executed with the cover of an Al layer 4. Next, an AU thin film is stuck in the degree of 1μm by a low DC current about at 45 deg.C and afterwards, DC electric plating is performed by a pulse-shaped high current. The current density depends on the number of bumps and it is 3-6mA/cm<2> for about one second. During plating, a bathtub is forcedly circulated. After plating, masks 5 and 47 are detached. The interconnection pattern of a surface 11 having a terminal edge 8 and smooth spherical projections 7 floated at a central part 9 is formed according to the combination and first contour of local voltage changes like this. Conductive tracks 17 and 18 on a supporting substrate 13 and the control circuit of the substrate 1 are connected through a bump 10. |
