Fail open semiconductors

Claim 1

A semiconductor unit comprising in combination; a semiconductor element having spaced substantially parallel faces between which current flow takes place in normal use and at least one semiconductor junction therebetween, the element being subject to failure to a short circuit state when its power rating is exceeded; a pair of spaced imperforate plates of conducting material complementary to and substantially coextensive with one of said faces, one of said plates being in abutting relation to said one face; a thin plate of electrically insulating material complementary to and substantially coextensive with said spaced plate and intimately sandwiched between said spaced plates; a pair of terminals seated against the other of said faces and the other of said spaced plates, the terminals being substantially coextensive in area with the faces and spaced discs to hold the element and the plates sandwiched therebetween, a plurality of fusible conducting ribbons extending between said spaced plates respectively, and located outboard the same and at peripherally spaced positions thereabout, the cross-section of said ribbons being such that they fuse and interrupt the circuit between the terminals when current flow indicative of semiconductor failure occurs, and a casing secured to the terminals to enclose and maintain the integrity of the assembly of the element and plates.