The present invention is directed to an improved electroplating method, chemistry, and apparatus for selectively depositing tin/lead solder bumps and other structures at a high deposition rate pursuant to manufacturing a microelectronic device from a workpiece, such as a semiconductor wafer. An apparatus for plating solder on a microelectronic workpiece in accordance with one aspect of the present invention comprises a reactor chamber containing an electroplating solution having free ions of tin and lead for plating onto the workpiece. A chemical delivery system is used to deliver the electroplating solution to the reactor chamber at a high flow rate. A workpiece support is used that includes a contact assembly for providing electroplating power to a surface at a side of the workpiece that is to be plated. The contact contacts the workpiece at a large plurality of discrete contact points that isolated from exposure to the electroplating solution. An anode, preferably a consumable anode, is spaced from the workpiece support within the reaction chamber and is in contact with the electroplating solution. In accordance with one embodiment the electroplating solution comprises a concentration of a lead compound, a concentration of a tin compound, water and methane sulfonic acid.