Patent ID: 6468893
Filing Date: 2002-10-22
Classification: H01L,H05K

Abstract:
A method of forming solder bumps, comprising the steps of:(a) forming first solder paste layers on respective electrodes or pads of a substrate by printing a solder paste to have a specific pattern on the electrodes or pads using a first mask with openings; (b) forming first solder bumps on the respective electrodes or pads of the substrate by melting the first solder paste layers due to heat for a while and by solidifying the first solder paste layers thus melted, after removing the first mask from the substrate; (c) forming second solder paste layers on the respective first solder bumps over the electrodes or pads of the substrate by printing a solder paste to have a specific pattern on the first solder bumps using a second mask with openings; and (d) forming second solder bumps on the respective electrodes or pads of the substrate by melting the first solder bumps and the second solder paste layers due to heat for a while to be integrated together and by solidifying the first solder bumps and the second solder paste layers thus melted and integrated, after removing the second mask from the substrate; the second solder bumps being larger than the first solder bumps; wherein each of the openings of the first mask has a volume in such a way that each of the first solder bumps has a height approximately equal to maximum size of a void to be suppressed according to size of a corresponding one of the electrodes or pads.