US 6,306,331 B1 · Ultra mold for encapsulating very thin packages

Abstract

A method of encapsulating a workpiece, particularly a microelectronic device, to achieve a very thin encapsulating layer and reduce the finished device size. The method includes positioning the workpiece in the mold cavity of a mold capable of reducing its volume while the mold compound is in a liquid state from a first volume, where mold compound may be easily added without creating voids, to a second smaller volume which defines the finished workpiece size. The second volume is below the size which would permit the void-free encapsulation of the workpiece in a conventional thermosetting plastic transfer molding machine. The mold may be opened in two stages to prevent damage to thin molded microelectronic devices by opening the perimeter of the mold first while the molded device is still being supported by large molding surfaces. The invention also includes the mold used in the method.

Claims18

Dependent claims

A method of encapsulating a workpiece comprising the steps of:

providing a mold cavity in a mold, the mold cavity having a first volume and a pair of opposed mold surfaces, the pair of opposed mold surfaces being inner surfaces on a pair of opposed cavity plates, the cavity plates including corresponding inclined ramp outer surfaces;
positioning the workpiece in the mold cavity;
holding the mold between a pair of opposed drive plates, each drive plate having an inclined ramp inner surface, the inclined ramp inner surfaces on the opposed drive plates defining a tapered clamp cavity bearing against the inclined ramp outer surfaces on the opposed drive plates;
adding mold compound to the mold cavity to encapsulate the workpiece;
reducing the volume of the mold cavity to a second volume less than the first volume by moving the mold into the tapered clamp cavity to reduce the distance between the opposed mold surfaces of the mold cavity;
and
curing the mold compound.

4 more elements

Dependencies are inferred from the claim text.

Ultra mold for encapsulating very thin packages

Life of this patent

Ultra mold for encapsulating very thin packages

Life of this patent

Abstract

Claims18