Thyristor with improved current and voltage handling characteristics

Claim 2

A controlled rectifier comprising: main current carrying semiconductive means and gate signal amplifying semiconductive means each having first, second, third, and fourth layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said second, third, and fourth layers of said main semiconductive means and said amplifying semiconductive means being integrally related, said first layer of said amplifying semiconductive means being annular and separating the surfaces of said second layers of said amplifying and main semiconductive means and said second layer surface of said main semiconductive means separating said first layers of said amplifying and main semiconductive means, means providing a low impedance electrical interconnection between said first layer of said amplifying semiconductive means and said second layer of said main semiconductive means, gate means in contact with said second layer surface of said amplifying semiconductive means, means formed by said first layer of said Amplifying semiconductive means to forestall turn off of said amplifying semiconductive means prior to turn on of said main semiconductive means including a current spreading avenue extending outwardly from said first layer of said amplifying semiconductive means and means for locating initial turn on and turn off of said gate signal amplifying semiconductive means angularly adjacent said current spreading avenue, and first and second main current carrying terminal means in contact with said first layer of said main semiconductive means and said fourth layers of said semiconductive means, respectively.

Claim 3

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of a pilot portion and a main portion connected by a bridge portion, a base layer adjacent said first emitter layer having a pilot gate surface portion and a main gate surface portion separated by said pilot portion of said first emitter layer, said main gate surface portion lying adjacent said main portion of said first emitter layer, gate means in contact with said pilot gate surface portion, means formed by said pilot portion of said first emitter layer to initiate conduction through said semiconductive element adjacent to said bridge portion of said first emitter layer, low impedance electrically conductive means interconnecting said pilot portion of said first emitter layer to said main gate surface portion of said adjacent base layer, and first and second main current carrying terminal means in contact with said main portion of said first emitter layer and said second emitter layer, respectively.

Claim 4

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of a pilot portion and a main portion connected by a bridge portion, a base layer adjacent said first emitter layer having a pilot gate surface portion and a main gate surface portion separated by said pilot portion of said first emitter layer, said main gate surface portion lying adjacent said main portion of said first emitter layer, gate means in contact with said pilot gate surface portion, means formed by said pilot portion of said first emitter layer to initiate conduction through said semiconductive element adjacent to said bridge portion of said first emitter layer, low impedance electrically conductive means interconnecting said pilot portion of said first emitter layer to said main gate surface portion of said adjacent base layer, and first and second main current carrying terminal means in contact with said main portion of said first emitter layer and said second emitter layer, respectively.

Claim 5

A controlled rectifier according to claim 2 in which said bridge portion of said first emitter layer exhibits a higher impedance than the remainder of said first emitter layer.

Claim 6

A controlled rectifier according to claim 2 in which said bridge portion is free of direct contact with any metallic conductor.

Claim 7

A controlled rectifier according to claim 2 in which said pilot portion of said first emitter layer is annular in configuration and said conduction initiating means constitutes a portion associated with an inner edge of said annular pilot portion and lying nearer said gate than any remaining portion of said pilot portion.

Claim 8

A controlled rectifier according to claim 2 in which said pilot portion of said first emitter layer is annular in configuration and said conduction initiating means constitutes a flat on the inner edge of said annular pilot portion.

Claim 9

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of a pilot portion, an auxiliary pilot portion, and a main portion, said auxiliary pilot portion and said pilot portion being integrally related through means providing an elevated impedance conductive interconnecting path therebetween, a base layer adjacent said first emitter layer having a pilot gate surface portion and a main gate surface portion separated by said pilot portion of said first emitter layer, said main gate surface portion lying adjacent said main portion of said first emitter layer and separating said pilot and said auxiliary pilot portions from said main portion of said first emitter layer, gate means in contact with said pilot gate surface portion, means formed by said pilot portion of said first emitter layer to initiate conduction through said semiconductive element adjacent to said auxiliary pilot portion of said first emitter layer, low impedance electrically conductive means interconnecting said pilot portion of said first emitter layer to said main gate surfacE portion of said intermediate layer, and first and second main current carrying terminal means in contact with said main portion of said first emitter layer and said second emitter layer, respectively.

Claim 10

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of a pilot portion, an auxiliary pilot portion, and a main portion, said auxiliary pilot portion and said pilot portion being integrally related through means providing an elevated impedance conductive interconnecting path therebetween, a base layer adjacent said first emitter layer having a pilot gate surface portion and a main gate surface portion separated by said pilot portion of said first emitter layer, said main gate surface portion lying adjacent said main portion of said first emitter layer and separating said pilot and said auxiliary pilot portions from said main portion of said first emitter layer, gate means in contact with said pilot gate surface portion, means formed by said pilot portion of said first emitter layer to initiate conduction through said semiconductive element adjacent to said auxiliary pilot portion of said first emitter layer, low impedance electrically conductive means interconnecting said pilot portion of said first emitter layer to said main gate surfacE portion of said intermediate layer, and first and second main current carrying terminal means in contact with said main portion of said first emitter layer and said second emitter layer, respectively.

Claim 11

A controlled rectifier according to claim 7 in which said auxiliary pilot portion is in contact with said low impedance electrically conductive means.

Claim 12

A controlled rectifier according to claim 7 in which said pilot portion of said one emitter layer is annular in configuration and said conduction initiating means constitutes a portion associated with an inner edge of said annular pilot portion and lying nearer said gate than any remaining portion of said pilot portion.

Claim 13

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of an annular pilot portion and a main portion, a base layer adjacent said first emitter layer having a pilot gate surface portion and a main gate surface portion separated by said pilot portion of said first emitter layer, gate means overlying said pilot gate surface portion, for gate signal transmission thereto, said main gate surface portion being comprised of a portion contacting an edge of said annular pilot portion and a plurality of finger portions radiating from said contacting portion in interdigitated relationship with said main portion of said first emitter layer, low impedance electrically conductive means interconnecting said annular pilot portion of said first emitter layer to said main gate surface portion of said adjacent base layer, first main current carrying terminal means in contact with said main portion of said first emitter and overlying said main gate surface portion and said low impedance electrically conductive means in spaced, nonconductive relation thereto, second main current carrying terminal means in contact with said second emitter layer of said semiconductive element, and said adjacent base layer being in low resistance ohmic contact with said first main current carrying terminal means adjacent a portion of said low impedance electrically conductive means lying between adjacent finger portions at a location most remote from the intersection of said main portion of said first emitter layer with said main gate surface portion.

Claim 14

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of an annular pilot portion and a main portion, a base layer adjacent said first emitter layer having a pilot gate surface portion and a main gate surface portion separated by said pilot portion of said first emitter layer, gate means overlying said pilot gate surface portion, for gate signal transmission thereto, said main gate surface portion being comprised of a portion contacting an edge of said annular pilot portion and a plurality of finger portions radiating from said contacting portion in interdigitated relationship with said main portion of said first emitter layer, low impedance electrically conductive means interconnecting said annular pilot portion of said first emitter layer to said main gate surface portion of said adjacent base layer, first main current carrying terminal means in contact with said main portion of said first emitter and overlying said main gate surface portion and said low impedance electrically conductive means in spaced, nonconductive relation thereto, second main current carrying terminal means in contact with said second emitter layer of said semiconductive element, and said adjacent base layer being in low resistance ohmic contact with said first main current carrying terminal means adjacent a portion of said low impedance electrically conductive means lying between adjacent finger portions at a location most remote from the intersection of said main portion of said first emitter layer with said main gate surface portion.

Claim 15

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of an annular pilot portion and a main portion surrounding and laterally spaced therefrom, a base layer adjacent said first emitter layer having a pilot gate surface located centrally of said annular pilot portion and a main gate surface portion separating said pilot portion and said main portion of said first emitter layer, centrally located gate means in contact with said pilot gate surface portion, said main gate surface portion being located nearer to the second emitter layer than is the surface of said first emitter layer, said main gate surface portion being comprised of a portion contacting an edge of said annular pilot portion and a plurality of finger portions radiating outwardly from said contacting portion in interdigitated relationship with said main portion of said first emitter layer, means in contact with said pilot portion of said first emitter layer to forestall turn off of said annular pilot portion prior to turn on of said main portion of said first emitter layer including a current spreading avenue extending outwardly from said annular pilot portion and means for locating initial turn on and turn off of said annular pilot portion angularly adjacent said current spreading avenue, low impedance eleCtrically conductive means interconnecting said annular pilot portion of said first emitter layer to said main gate surface portion of said adjacent base layer, first main current carrying terminal means in contact with said main portion of said first emitter and overlying said main gate surface portion and said low impedance electrically conductive means in spaced, nonconductive relation thereto, said adjacent base layer being in low resistance ohmic contact with said first main current carrying terminal means at at least one location remote from said annular pilot portion and said low impedance electrically conductive means, second main current carrying terminal means in contact with said remaining emitter layer of said semiconductive element, and housing means in contact with said terminal means and surrounding said semiconductive element to protect said junctions against contamination.

Claim 16

A controlled rectifier comprising: a semiconductive element having first and second emitter layers and two intermediate base layers, adjacent of said layers being of opposite conductivity type and forming junctions therebetween, said first emitter layer being comprised of an annular pilot portion and a main portion surrounding and laterally spaced therefrom, a base layer adjacent said first emitter layer having a pilot gate surface located centrally of said annular pilot portion and a main gate surface portion separating said pilot portion and said main portion of said first emitter layer, centrally located gate means in contact with said pilot gate surface portion, said main gate surface portion being located nearer to the second emitter layer than is the surface of said first emitter layer, said main gate surface portion being comprised of a portion contacting an edge of said annular pilot portion and a plurality of finger portions radiating outwardly from said contacting portion in interdigitated relationship with said main portion of said first emitter layer, means in contact with said pilot portion of said first emitter layer to forestall turn off of said annular pilot portion prior to turn on of said main portion of said first emitter layer including a current spreading avenue extending outwardly from said annular pilot portion and means for locating initial turn on and turn off of said annular pilot portion angularly adjacent said current spreading avenue, low impedance eleCtrically conductive means interconnecting said annular pilot portion of said first emitter layer to said main gate surface portion of said adjacent base layer, first main current carrying terminal means in contact with said main portion of said first emitter and overlying said main gate surface portion and said low impedance electrically conductive means in spaced, nonconductive relation thereto, said adjacent base layer being in low resistance ohmic contact with said first main current carrying terminal means at at least one location remote from said annular pilot portion and said low impedance electrically conductive means, second main current carrying terminal means in contact with said remaining emitter layer of said semiconductive element, and housing means in contact with said terminal means and surrounding said semiconductive element to protect said junctions against contamination.