Which thermal interface for your CPU, GPU or FPGA?

By searching thermal interface material on the internet you will find a huge panel of product with different prices and performances for thermal management.

Don't worry we are here to help you to find the best technological solution for your project.

First, let's have a look at the different thermal interfaces:

Thermal interface or gap filler:

This is the most common solution due to the facility to use it. It can be packaged on sheets are on reels.

This material is a silicone sheet loaded with thermal conductive particles. These can be metallic as Zinc, Aluminium, Silver or ceramic. It changes the conductivity and the electronic insulation (voltage breakdown).

It exists also alternatives without silicone oil for really specific application as military, or optic projects (in these cases the thermal interface must not degas any material).

The advantage of this material :

• Can be cut following specific design
• Easy to apply on a component (PCB, GPU, PCB)
• High performance
• Different thickness and hardness
• Shock absorption

Disadvantages:

• Might be too hard for some application
• Require to know what is the dimensions to cover with the thermal interface.

Thermal paste or thermal grease:

This product is often used for CPU and GPU thermal maintenance for example. It ensures the interface between the heat-sink and the hot component.

This is the same material as the solid gap filler but this one is "pasty". It is packaged on syringes, tubes, bucket or dispensed using a dispensing robot (Compelma provides this service).

The advantage of this product:

• Perfect for prototyping
• Really soft
• Low thickness
• Easily packaged
• Can be dispensed on any small cavities.

Disadvantages:

• Might flow over the component if there is to much grease or paste
• No compression stop (some options as glass bead can be integrated to create a compression stop)
• No shock or mechanical absorption.

Graphite interfaces:

These material is the same as the one in the pencil point. It is composed of several microscopic carbon sheets laminated together.

This material have a really high thermal performance (>1 000W/m.K) but is really hard (no shock absorption) but is also really thin.

This product is also conductive so it might not be required for some project when electric insulation is required.

‍

If you still have some question about thermal interfaces, our team would be happy to help!

We can also provide samples if you have some tests to do.