An apparatus and a method for selectively etching an encapsulant forming a package of resinous material around an electronic device includes an electronic device package mountable on the etch head; a conductive electrode in electrical contact with package leads of the electronic device package to apply a first voltage to the package leads of the electronic device; a first pump configured to pump a first quantity of the etchant solution from the source into the etch head where the etchant solution is electrically biased to a second voltage different from the first voltage. An etch cavity is formed on an exterior surface of the electronic device package. When the etchant solution has etched through an exterior surface of the electronic device package, the conductive bond wires of the electronic device is prevented from being etched by the applied first voltage.