High power transistor having emitter pattern with symmetric lead connection pads

Claim 1

A high current high power transistor comprising a thin chip of semiconductor material having first and second flat parallel end surfaces; a first region of a first conductivity type extending from said first end surface and defining the collector region of said transistor; a second region of the other of the conductivity types defining the base of said transistor and extending across a central region of said chip and meeting said first region in a generally flat P-N junction; at least one emitter region of said first conductivity type extending into said second end surface of said chip and including a plurality of spaced elongated fingers extending laterally from the opposite sides of an enclosed rectangular area; said enclosed rectangular area having first and second centrally disposed enlarged, spaced connection pad areas having generally square configurations and each defined by the foreshortening of the roots of at least three of the fingers of said spaced elongated fingers which extend from said enclosed area; the material of said second and base region extending between said spaced elongated fingers of said emitter region and terminating on said second end surface of said chip and defining an elongated base-to-emitter junction which extends to said second end surface of said chip; a collector electrode connected to said first end surface of said chip; a base electrode connected to said second surface of said chip and atop said material of said second region; a base lead connected to said base electrode of said chip; an emitter electrode connected to said second end surface and extending over said at least one emitter region at said second end surface and electrically separated from said base electrode, and first and second flexible emitter leads connected to said first and second connection pad areas and connected to one another to serve as the emitter terminal for said transistor.