First Coreflow Prototype Delivered for Project Subsurface

This month, TWI and its partners have produced the first CoreFlow^TM prototype for project SubSurface; a liquid-cooled heat sink for a power electronics applications.

The design is based on an existing product that would traditionally require four manufacturing operations:

• (1) Machining an open channel in an aluminium substrate for electronic assembly
• (2) Bending a copper pipe for coolant circulation
• (3) Pressing/swaging the copper pipe into the pre-machined channel, along with a thermal conductive paste to enable conduction at the interface between the two materials
• (4) Skimming the top surface of the assembly to ensure an even contact between the electronic devices and the aluminium and copper parts

CoreFlow^TM enabled the incorporation of the cooling channel directly into the aluminium plate in a single step, using fewer raw materials and in a fraction of the total cycle time. The component is also lighter and easier to recycle than with the traditional approach.

An initial x-ray inspection showed that the channel path is repeatable/consistent, while a pressure test qualified the part for additional assessment. In the coming months, the team will assemble live electronics and compare its thermal performance with that of an equivalent plate produced via the traditional approach. This will be complemented with an economic assessment. The team expects the data gathered will fulfil the requirements to achieve Technology Readiness Level 4 for this particular application.

The work is being delivered in partnership with PSL Assemblies and Hybrid Manufacturing Technologies. In parallel to the product development activities, the project will also deliver an off‑the‑shelf system for deploying CoreFlow^TM on mainstream CNC milling machines.

The SubSurface project has received funding from Innovate UK under grant No 10023786.