Abstract: Apparatus for selectively etching a resinous encapsulant wall forming an electronic device package includes etching solution source; an etching assembly including an etch head and orifice for directing etchant solution onto an exterior surface of the package; a cover extending over an etch plate mounting the etch head and forming an etching chamger; a frame on the etch plate and in the chamber for mounting the package such that a package exterior surface is mounted against the etch head, the frame including a sealing gasket between the frame and the etch head and surrounding the orifice; and a ram for pushing and sealing the frame against the etch head peripherally outwardly of and surounding the etch head orifice. In a second embodiment the frame is an etch cup having a well with or without apertures for receiving package leads. In one embodiment the frame mounts a ball grid array package, the frame including a handle perventing contact of heated solder balls.