Published on: 01/11/2016

Discover the complete IXYS UK Westcode Thyristor Range

IXYS UK Westcode are a manufacturer of high power Thyristor capsules (GTO, fast & standard recovery), diode capsules (fast & standard recovery) and IGBT capsules.

IXYS UK Westcode Thyristor Group Image

One of the essential advantages of power semiconductor modules compared to discrete designs is the electrical isolation between the baseplate of the module and the parts subject to voltage (3.6-4.8kV tested). This enables the mount-down of any number of the same or different modules on a common heat sink. It is sufficient to use standard housings with appropriate accessories for designing compact power converter operating from AC mains up to 690V.

Plastic Housing with DCB Sub-strate

IXYS have managed to simplify the conventional multilayer module construction by the DCB (Direct Copper Bonding) technique.

The benefits of using the DCB substrate include:

• Top-side electrical terminals with captured nuts
• Series-connected diode/diode, thyristor/thyristor modules
• Easy assembly

All thyristor modules with DCB ceramic base contacts are available in volume with two standardised twin plugs (2.8mm x 0.8mm) for gate and auxiliary cathode control terminals (version 1). Modules in TO-240 housing of the version 8 are delivered with gate plugs only (without auxiliary cathode terminal; mounting screws are available on request). The module housing is designed for adequate clearance and creepage distance.

New Generation Silicon Chips

All IXYS chips are designed by applying separation diffusion processes so that the zones responsible for the surface field strength are located at the upper chip side. This results in the capability of soldering the entire chip area onto the the DCB ceramic substrate without molybdenum strain buffer, which in turn, leads to good stability of the chips as well as to to large area heat dissipation if a load is applied.

All zones at the edges which are decisive for the blocking stability are coated with passivation glasses the coefficient of expansion of which match that of silicon. Silicon chips increasingly use planar technology with guard rings and channel stoppers to reduce electrical surface fields. This chip design supercedes the design of thyristor chips which were fabricated with passivation moats so that modules of the new series designed with the updated state-of-the-art utilise planar passivated chips processed by separation diffusion techniques. The contact areas of the chips possess physical vapour deposited metal layers. For the user the improved properties are:

• Excellent long-term stability of blocking currents and blocking voltages.
• Increased lifetime of the internal soldered connections
• High power cycling capability (>50 000).

The thyristor/diode chips have been optimised with regards to their turn off parameters: decreasing the carrier lifetime results in reduced stored charges QS, which in turn significantly reduces the requirements for RC-snubbers for over-voltage protection. Cost reduction and improved efficiency are the benefits of these characteristics. By re-developing the silicon chips, improvements of the firing characteristics were achieved by specifying a higher “gate current not to fire” IGD resulting in a substantially less susceptibility to misfiring. This leads to greater safety of operation and higher reliability of the equipment.

GD Rectifiers are IXYS UK Westcode’s Official UK Distributor; they stock a wide range of Components. Heat Sinks and Hardware.

GD Rectifiers offers a broad range of IXYS UK Westcode Thyristor products to suit your application. These include phase control, fast turn-off, distributed gate, medium voltage and asymmetric thyristors. This range include the new WESPACK outline for phase control thyristors, with voltage ratings up to 2.2kV, giving maximum power rating for weight and volume, without compromising on quality and reliability.

IXYS UK Westcode Thyristor Product Overview:

Phase Control Studs:        131Ams to 416Amp, 400-1600V

Phase Control Capsules:        255Amps to 6974Amps, 800-4500V

Fast Turn-Off Studs:        128Amps to 431Amps, 400-1200V – 10 to 30uS

Fast Turn-Off Capsules:        295Amps to 1007Amp, 400-1200V – 10 to 30uS

Distributed Gate Capsules:      472Amps to 4001Amps, 800-4500V – 10 to 300uS

Medium Voltage Capsules:    349Amps to 3503Amps, 3000-6500V

Asymmetric Capsules:        516Amps and 1237Amps, 2400-2800V

An official distributor for IXYS UK Westcode

Browse the complete IXYS UK Westcode Thyristors product range here.

For further information on all IXYS Thyristor products click here or alternatively call our friendly sales team on: 01444 243 452.

Find out more about the latest GD Rectifiers product range here.