Patent ID: 6979636
Filing Date: 2005-12-27
Classification: H01L,H05K

Abstract:
1. A method for forming heightened solder bumps on a circuit board, which has a surface formed with a plurality of pads and a solder resist thereon, and the pads are exposed from the solder resist, the method comprising the steps of: overlaying a first mask on the surface of the circuit board, the first mask having a plurality of first holes corresponding to the pads of the circuit board respectively; filling the first holes of the first mask with first solder paste by a squeegee in a quick and light squeeze manner; removing the first mask; applying a first reflow process to the circuit board, whereby the first solder paste remaining on the circuit board forms into a plurality of first solder bumps on the pads of the circuit board respectively; overlaying a second mask on the surface of the circuit board, the second mask having a plurality of second holes corresponding to the first solder bumps respectively, wherein the second mask has a thickness greater than the thickness of the first mask; filling the second holes of the second mask with second solder paste by the squeegee in a slow and hard squeeze manner, wherein the second solder paste has a density greater than the density of the first solder paste; removing the second mask; and applying a second reflow process to the circuit board, whereby the second solder paste remaining on the circuit board integrates with the first solder bumps respectively to form the heightened solder bumps on the pads.