Abstract: A vapor generation system includes a supply of liquid; an inert gas stream; an aspirator for aspirating the liquid into the gas stream; a heater for heating the gas stream upstream from the aspirator to a temperature such that aspirated liquid is vaporized in the aspirator to form an inert gas and liquid vaporous mixture; and a mixture outlet for flowing the vaporous mixture against a surface of a workpiece. In a particular application a nitrogen gas stream is heated in a heat exchanger and flows through an aspirator/evaporator to vaporize pumped pulses of hydrofluoric acid in the heated flow stream. The resultant vaporous mixture forms a suitable vaporous etchant for removing silicon dioxide contaminates from a conveyor belt which is employed to convey semiconductor wafers through a chemical vapor deposition processing chamber.

Abstract: An apparatus and method for selectively etching an encapsulant forming a package of resinous material around an electronic device includes a source of etchant solution and an etching assembly including an etch plate and a bell jar or cover, the etch plate and bell jar forming an etching chamber. Optionally, an etch cup or fixture is supported by the etch head or the electronic device package is mountable in the chamber directly on the etch head. A source of pressurized gas such as nitrogen provides a positive pressure about 2 PSI to the bell jar and to flow the etchant solution through the etch head and onto an exterior surface of the electronic device package so that the encapsulant is etched and when break out occurs on a side wall of the package, the pressure in the bell jar is vented to a waste reservoir and the pressure at the etchant solution source is reduced so that etchant solution flow is instantly stopped to prevent any damage to the electronic device by excessive etching.

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.

Abstract: An apparatus and method for selectively etching an encapsulant forming a package of resinous material around an electronic device includes a source of etchant solution and an etching assembly including an etch plate and a movable cover, the etch plate and cover forming an etching chamber. An etch head is supported by the etch plate and the electronic device package is mountable in the chamber on the etch head. In a first mode of operation a displacement pump pumps a first quantity of etchant solution into the etch head and in a second mode of operation the displacement pump agitates at least part of the first quantity of etchant solution repeatedly into and out of an etched cavity formed on an exterior surface of the electronic device package by reaction of the etchant solution with the resinous material. A waste reservoir and a waste outlet extending from the etch head to the reservoir is also provided. The etch head is easily removable from the etch plate by removal of an etch head retainer.