Lead frame design

Claim 2

Structure as in claim 2, wherein each group of leads contains three leads, said selected lead comprising the collector lead, and said multiplicity of leads comprising base and emitter leads said base and emitter leads being located on opposite sides of said collector lead and being attached to said collector lead by a shorting bar, said heat sink serving also as the collector contact.

Claim 3

Structure as in claim 3 wherein each group of leads contains a semiconductor die placed on said layer of solder on said heat sink, such that said die is held between said heat sink and the tongues of metal extending from said base and emitter leads, said tongues of metal being pressed against contact regions on said semiconductor die by the spring force in said S-shaped bend in said collector lead.

Claim 4

Structure as in claim 4 wherein in each group of leads said semiconductor die is attached by solder to said heat sink and to said tongues extending from said base and emitter leads.

Claim 5

Structure as in claim 5 wherein each group of leads said semiconductor die and selected portions of said tongues of metal and said heat sink have been coated with a junction coating to protect said semiconductor die.

Claim 6

Structure as in claim 6 wherein each of said groups of leads, together with the corresponding semiconductor die and junction coating has been encapsulated in plastic, thereby to provide a plastic package for the semiconductor die and its three leads.

Claim 7

Structure as in claim 7 wherein each semiconductor die contains a transistor.

Claim 8

Structure as in claim 7 wherein each semiconductor die contains a diode.

Claim 9

Structure as in claim 7 wherein said heat sink extends from the top of said plastic package, and said collector, base and emitter leads extend from the bottom of said plastic package, said heat sink contains a hole therein for use in mounting said package, and the shorting bar connecting said collector, base and emitter leads has been removed thereby to electrically isolate each lead from said package except as said leads are interconnected through said semiconductor die.

Claim 10

A group of leads comprising a heat sink portion located in a first plane, a selected lead attached to and extending from said heat sink, the portion of said selected lead adjacent said heat sink forming an S-shaped bend such that the remainder of said first lead occupies a second plane parallel to but removed from said first plane, and a multiplicity of leads attached to said selected lead by temporary supporting material, each of said multiplicity of leads being in said second plane and each containing a first end above said heat sink, a tongue of metal extending from each first end in said second plane away from said selected lead, each tongue of metal bending down toward said first plane and back towards said selected lead to form a U-shaped bend, and each tongue containing on its end a coating of solder.