Abstract: Molding carrier structures to leads of existing semiconductor packages is accomplished by molding at temperatures which maintain approximately matched thermal expansion between an encapsulating material and leads of the semiconductor package. The matched thermal expansion is provided by molding at temperatures below that which is required for glass transition of the encapsulating material. Molding at such temperatures is facilitated by a molding assembly that has a molding pot with an irregular shaped bottom which fluidizes the encapsulating material at low temperatures. Molding at temperatures that essentially match thermal expansion between the package's leads and the encapsulating material prevents damaging the leads of the package.

Abstract: An elastic material covering an outer surface of a cavity plate but not covering any clamping surfaces of the cavity plate or the inner surface of the cavity plate is used to eliminate use of a dam bar in a lead frame. In an embodiment in accordance with the present invention the elastic material provides a supplementary seal to the clamping surfaces of the cavity plate and a primary seal in spaces between leads of the encapsulated lead frame. In a method of using the present invention, the elastic material is placed between the mold base and the cavity plate. A semiconductor lead frame to be encapsulated is placed in cavities provided by the cavity plate. The mold is closed so that clamping surfaces of the cavity plate clamp directly onto the leads. The elastic material deforms under pressure to compensate for any dimensional variations of the mold plates or lead frame and completely seals the space between leads.

Abstract: A method fpr removing coatings from surfaces without damaging the underlying surface includes placing a surface having material to be removed thereon into a plasma reactor and exposing it to a gaseous plasma comprising a reactive halogen species. The reactive halogen species may be derived from one or more of many well known halogen gases. An optional step of cleaning the coating prior to exposure to the halogen plasma is recommended.

Abstract: A method for removing nitride coatings from metal tooling and mold surfaces without damaging the underlying base metal includes placing the nitride coated metal surface into a plasma reactor and subjecting it to a gaseous plasma comprising a reactive fluorine species. The reactive fluorine species may be derived from one or more of many well known gases. An optional step of cleaning the nitride coating is recommended.

Abstract: A method for bonding which comprises the step of heating a bottom thermode to a temperature of approximately 150.degree. C. The bottom thermode is then pulse heated to approximately 350.degree. C. while a die and lead frame are disposed above the lower thermode. An upper thermode, which may remain unheated, is then lowered to cause contact between the lead frame and the contacts of the die. The lower thermode then returns to a temperature of approximately 150.degree. C. The pulse heating of the lower thermode lasts for approximately 1-3 seconds.