1. Water cooling assembly of heat sink and device

The cooling mode of assemblies include natural cooling with heat sink, forced air cooling and water cooling. In order to enable the device employ the rated performance reliably in application, it is necessary to choose a suitable water cooling heatsink and assemble it with device properly. Such to ensure the thermal resistance Rj-hs between heat sink and thyristor/diode chip meets the cooling requirement. The measurements should be considered as below:

1.1 The contact area of the heat sink must match the size of device to avoid flattening or crooked damage of the device.

1.2 The flatness and cleanness of heat sink contact area must be highly finished. It is recommended that the surface roughness of the heat sink is less than or equal to 1.6μm, and the flatness is less than or equal to 30μm. During assembly, the contact area of device and heat sink should keep clean and free of oil or other dirt.

1.3 Make sure the contact area of device and the heat sink are basically parallel and concentric. During assembly, it is necessary to apply the pressure through the centerline of the component so that the press force is evenly distributed over the entire contact area. In manually assembling, it is recommended to use a torque wrench to apply even force to all tightening nuts in turn, and the pressure should meet the recommended data.

1.4 Please pay more attention to check the contact area is clean and flat if repeat using the water cooling heat sink. Make sure there is no scale or blockage in the water box cavity, and especially no sagging on contact area surface.

1.5 The assembly drawing of water cooling heat sink

2. Configuration and models of heatsink

Usually we will use SS water-cooled series and SF air-cooled series as well various special customization component heatsink to cool the power semiconductor devices. Please refer to the table below for the standard heatsink models which are configured and recommended according to the on-state average current of the devices.

The SF series air-cooled heatsink is selected under the condition of forced air cooling (wind speed ≥ 6m/s), and the customer should choose according to the actual heat dissipation requirement and reliability. Generally it’s not recommended to use air-cooled heatsink to cool the device above 1000A. If an air-cooled radiator is used actually, the rated current of the device must be derated in application. If there is no special requirements of application, the heatsink is usually selected according to the standard configuration. If any special requirement from the customer, please contact with us feel free.

3. Recommendation

The most important issue to ensure the reliable performance of circuit is to select the qualified device and heat sink. The high power thyristor and high power diode manufactured by Runau Semiconductor are highly lighted in line frequency applications. The featured voltage ranges from 400V to 8500V and current ranges from 100A to 8KA. It’s excellent in strong gate trigger pulse, pretty balance of conducting and recovery characteristics. The water cooling heat sink is designed and manufactured by CAD and CNC facilities. It’s helpful to enhance the operating performance of devices.