Method of fabrication of a multi-component solder column by blocking a portion of a through hole in a mold

A method for molding solder columns and forming the solder columns on a substrate, the method comprises the steps of:

• providing a mold having at least one through opening extending from the upper surface to the lower surface of said mold;
• positioning the mold so the through openings at the upper surface remain open and the lower surface is adjacent to a blocking means for blocking a portion of the through opening;
• forcing a first molten solder having a first melting point into the through openings by a forcing means from the upper surface and filling the through opening except for the portion which is blocked by the blocking means;
• solidifying the first solder;
• removing the blocking means and forcing a second molten solder having a second melting point into the through openings from the lower surface filling the remainder of the through openings with the second solder;
• solidifying the second solder;
• positioning the surface of the mold containing the lower melting point solder adjacent to the substrate;
• heating the substrate and mold so that the lower melting point solder melts;
• bonding the substrate and the solder column;
• cooling the mold;
• and
• removing the mold leaving the solder columns on the surface of the substrate.