Method for forming bump and semiconductor device

摘要

The presentinvention intends to form bumps of desired size and shape by simple steps. For this end, pads 2 are formed on a printed circuit board 1 at the same space as pads on a semiconductor chip 5. Then, the entire upper surface of the printed circuit board 1 is covered with a rsist 3 except pad formed areas. The surface of the printed circuit board 1 covered with the resist 3 is then oriented downwardly and is sprayed with molten solder from the bottom side. The molten solder attaches the pad formed surface on the printed cuircuit board 1 and ideal semispherical bumps 4 are formed by the influence of gravity. The printed circuit board 1 formed with the bumps 4 is aligned with the pads 6 on the semiconductor chip 5 to be transferred into a high temperature oven. The bumps 4 are molten for jointing the semiconductor chip 5 and the printed circuit board 1.