Hi ,

Can any one suggest a appropriate mounting instructions for the above part number. Also the thermal interface material for this thyristor which is TO-247 package. Suggest a suitable thermal epoxy / thermal grease to get mount on heat sink. Since the back side of the part is anode part which is live part.

Hello @shreelekha.koteeswar,

Welcome to the Techform Community!

To isolate the backside of the TO-247 package, we have thermal pads that have been die-cut for the TO-247 size here. These pads are designed to be grease-free.

Mounting to the heatsink can be done similarly to the TO-220 shown below. From the snip, Item 2 would not be used.

Snip from datasheet

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Hi Many thanks for the suggestion. But still I am looking for an alternative other than thermal interface pad. Because we are experiencing shorts since the mounting hole of thermal pad is larger compared to the hole of the heat sink. Was there any other options or its better to use thermal grease and then thermal pad sticked to it and then thyristor. Do you have any suggestions of interface sheets so that we can laser cut -in house. or thermal epoxy / bond

A variety of materials including some shown here are available in larger sizes, and are designed to provide electrical insulation between a device and its heat sink. Care should be used when selecting and designing with such materials because of the possibility of puncture or cut-through.

Older mounting techniques using screws through a device body are becoming less popular, compared to spring-based techniques of the kind pictured below. Depending on the application, use of a metal bar and screws to create a clamp type mechanism with a similar effect is also common.

Elaborating on the heatsink spring clip point, here’s a link to a number of options we offer.

Further examples:


Hi Thanks for the link. But still I am concerned if the discrete thyristor back side anode part is non-isolated one / live part. Suggest whether thermal grease or thermal gap pad which is sufficient to mount those onto heat sink.

There is no grease product available that will provide electrical insulation between the metal tab on the transistor and a heat sink.

The interface materials linked previously are composite materials designed to provide a thermal interface function while also providing electrical insulation. Whether any of them are sufficient for your needs is a decision that you must make, based on the requirements of your application and the product specifications given in the datasheet.