Abstract: A semiconductor package contains a metal leadframe that has been specially treated by roughening it with a chemical etchant. The roughening process enhances the adhesion between the leadframe and the molten plastic during the encapsulation of the leadframe and thereby reduces the tendency of the package to separate when exposed to moisture and numerous temperature cycles. In one embodiment, the leadframe made of copper is roughened with a chemical etchant that contains sulfuric acid and hydrogen peroxide.

Abstract: A series of grooves are etched in a leadframe to be used in fabricating a group of semiconductor packages at locations where the leadframe will later be sawed to separate the semiconductor packages. In variations of the process, the grooves may be wider or narrower than the kerf of the saw cuts and may be formed on the side of the leadframe facing towards or away from the entry of the saw blade.

Abstract: A flat no-lead semiconductor die package contains a plurality of studs that protrude from the bottom surface of the capsule and act as electrical contacts, allowing the package to be mounted on a flat surface such as a printed circuit board, while permitting external circuit to be located on the flat surface directly beneath the package. The package may or may not contain a die-attach pad. The die may be mounted flip-chip style on the stud contacts and die-attach pad. A method of fabricating the package includes etching an upper portion of a metal sheet through a mask layer, attaching dice at locations on the surface of the metal sheet, forming a layer of molding compound over the dice, etching the lower portion of the metal sheet through a second mask layer, and separating the packages with a dicing saw or punch tool.

Abstract: A semiconductor package contains a metal leadframe that has been specially treated by roughening it with a chemical etchant. The roughening process enhances the adhesion between the leadframe and the molten plastic during the encapsulation of the leadframe and thereby reduces the tendency of the package to separate when exposed to moisture and numerous temperature cycles. In one embodiment, the leadframe made of copper is roughened with a chemical etchant that contains sulfuric acid and hydrogen peroxide.

Abstract: A semiconductor package contains a metal leadframe that has been specially treated by roughening it with a chemical etchant. The roughening process enhances the adhesion between the leadframe and the molten plastic during the encapsulation of the leadframe and thereby reduces the tendency of the package to separate when exposed to moisture and numerous temperature cycles. In one embodiment, the leadframe made of copper is roughened with a chemical etchant that contains sulfuric acid and hydrogen peroxide.

Abstract: A layer of nonconductive epoxy is applied to a semiconductor wafer by a screen-printing process before the wafer is separated into individual dice or chips. The epoxy layer is applied as a number of sublayers. Each of the sublayers is cured, except for the final sublayer, which is partially cured. After the epoxy layer has been applied to the wafer, the wafer is separated into individual dice. Each of the dice is then attached to a die pad, a plurality of leads, or another die, using the preformed epoxy layer, by pressing the die against the die pad, leads or die at a selected force and temperature. Applying the epoxy layer to the wafer in the manner described, before dicing, allows it to be made significantly thicker than a conventionally formed epoxy layer. This prevents a leakage current between the die and another element on which the die is mounted.