Semikron SEMIPACK 1 Dual Thyristor Module — Model SKKT57B12E

The Semikron SKKT57B12E is a high-reliability, dual-SCR (Silicon Controlled Rectifier) thyristor module engineered for heavy-duty phase control, power regulation, and automation applications. Housed in the industry-standard SEMIPACK 1 package, this module features a thyristor-thyristor (SCR doubler) circuit configuration optimized for high-capacity protection and control infrastructure.

The device is constructed with a flame-retardant, high-dielectric cream polymer casing. The top profile features three primary heavy-gauge threaded power terminals (marked 1, 2, and 3) positioned alongside fast-on auxiliary control gate/cathode pins for secure signal coupling. An explicit internal circuit schematic and a matrix tracking code are etched directly onto the side of the housing for straightforward field verification.

Key Features

Dual-SCR Doubler Topology: Integrates two series-connected phase-control thyristors within a single module, providing a compact building block for standard rectifier and AC power manipulation circuits.
Superior Thermal Dissipation: Utilizes an advanced aluminum oxide ( $Al_2O_3$ ) ceramic isolated metal baseplate that maximizes heat transfer to external sinks while ensuring 3000 Vrms electrical isolation.
Hard Soldered Joints: Constructed with precision hard-soldered internal connections, significantly increasing reliability and thermal cycling lifetime under intensive load shifts.
Global Safety Certifications: Fully recognized under UL file number E 63 532, verifying compliance with international industrial safety requirements.

Technical Specifications

Feature	Specification
Product Type	Dual Thyristor (SCR-SCR) Power Module
Manufacturer	Semikron Danfoss
Model / Part Number	SKKT57B12E (MFG Item: 230B1677)
Package Type	SEMIPACK 1
Repetitive Peak Voltages ( $V_{RRM}/V_{DRM}$ )	1200 V
Average On-State Current ( $I_{TAV}$ )	50 A (at Case Temperature $T_C = 85^circtext{C}$ )
Continuous RMS Current ( $I_{TRMS}$ )	95 A max.
Surge On-State Current ( $I_{TSM}$ )	1250 A (at $T_{vj} = 125^circtext{C}$ ; 10 ms pulse)
Critical Rate of Rise of Voltage ( $dv/dt$ )	$1000text{ V/}mutext{s}$
Max. Virtual Junction Temperature ( $T_{vj}$ )	-40°C to +125°C
Isolation Voltage ( $V_{isol}$ )	3000 Vrms (AC for 1 minute)
Dimensions (L x W x H)	$93text{ mm} times 20text{ mm} times 30text{ mm}$
Weight	Approx. 95 grams

Applications

AC Motor Soft Starters: Regulating voltage ramping profiles in industrial motor starters to minimize high inrush currents and mechanical wear.
Industrial Temperature Control: Governing heavy resistive heating elements inside industrial kilns, polymer ovens, and chemical process reactors.
DC Motor Drives: Serving as the core rectification and speed-control bridge component for heavy machine tools and manufacturing line positioners.
Professional Studio & Theater Dimming: Delivering smooth, low-noise phase-angle power control for high-wattage lighting grids and entertainment setups.