Abstract: A method for removing Ball Limiting Metallurgy (BLM) layers from the surface of a wafer in the presence of Pb/Sn solder bumps. In one embodiment, the BLM comprises two layers: titanium and copper. After Pb/Sn solder bumps have been formed over the electrical contact pads of the wafer, the BLM copper layer is etched with a H.sub.2 SO.sub.4 +H.sub.2 O.sub.2 +H.sub.2 O solution. While removing the copper layer, the H.sub.2 SO.sub.4 +H.sub.2 O.sub.2 +H.sub.2 O etchant also reacts with the Pb/Sn solder bumps to form a thin PbO protective layer over the surface of the bumps. When the copper layer has been etched away, the titanium layer is etched with a CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O solution. The PbO layer formed over the surface of the Pb/Sn solder bumps remain insoluble when exposed to the CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O etchant, thereby preventing the solder bumps from being etched in the presence of the CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O etchant.