US Patent 7954693 Method of treating and probing a via

A method of treating a via connected with a substrate and a method of probing the via are disclosed. A pattern of a lead-free solder paste is applied around a hole of the via without completely covering a pad of the via. The paste is reflowed to form a pattern of a lead-free solder on a pad that covers only a portion of a surface area of the pad and is positioned around the hole. The solder may be substantially symmetrically positioned around the hole. A flux generated during reflow is insufficient to plug the hole. The lead-free solder can be probed by a blade probe including collinear first and second edges and having a preferred orientation relative to the pattern of the lead-free solder.