Abstract: A method and apparatus are disclosed for selective removal of a conformal coating from the solder balls of grid array packages such that the benefits of the coating are realized. An ancillary benefit of the invention is improved process-ability of the grid array package by improving the mechanical containment of the solder during the reflow process and improved electrical isolation between the individual solder attachment points. For example, a method for coating a ball grid array is provided, which includes coating the ball grid array with a thin layer of parylene. Next, the solder ball side of the part is butter smeared or squeegeed with a water soluble coating and assembled wet. A mask having holes in the same pattern as the balls in the grid, and a thickness that is about 80% of the height of the balls, is applied to the solder ball side of the part. This side of the part is then butter smeared again with the water soluble coating, and the entire assembly is allowed to dry.