Senior Thermal Engineer

About Graphcore

At Graphcore, we’re building the future of AI compute.We’re a team of semiconductor, software and AI experts, with deep experience in creating the complete AI compute stack - from silicon and software to infrastructure at datacenter scale.As part of the SoftBank Group, backed by significant long-term investment, we are delivering key technology into the fast-growing SoftBank AI ecosystem.To meet the vast and exciting AI opportunity, Graphcore is expanding its teams around the world.We are bringing together the brightest minds to solve the toughest problems, in a place where everyone has the opportunity to make an impact on the company, our products and the future of artificial intelligence.

Job Summary 

We are seeking an experienced engineer with expertise in thermal design, validation, and system integration for AI and HPC liquid-cooled servers. This role spans board-level, server-level, and rack-level applications, covering both air and liquid cooling technologies. This is a hands-on, multi-functional role that requires collaboration with silicon packaging, mechanical design, module assembly, and manufacturing partners to deliver reliable, scalable, and high performance thermal solutions at volume. 

The Team

The role will be as part of the Manufacturing Technology team at Graphcore. This team belongs to the Operations group and has members in Bristol, Cambridge and Taiwan. The team is responsible for developing and maintaining robust manufacturing processes at the wafer foundry, package assembly, and PCBA and server blade build subcontractors based in Taiwan. 

Responsibilities and Duties

• Collaborate with system, packaging, and mechanical build groups to outline and validate thermal architectures for high-power AI/HPC products. 
• Lead DFM (Design for Manufacturing) and DFA (Design for Assembly) reviews for thermal components and subsystems, including heatsinks, vapor chambers, cold plates, and manifolds. 
• Work closely with design teams and cooling solution vendors to translate prototype thermal designs (air and liquid cooling) into manufacturable, testable, and serviceable solutions suitable for high-volume production. 
• Partner with suppliers and contract manufacturers to qualify materials, processes, and production methods for thermal assemblies. 
• Work with Quality teams to define and conduct reliability validation, failure root cause analysis, and to implement corrective actions for manufacturing or field issues. 
• Develop and maintain manufacturing documentation and inspection criteria for thermal integration. 
• Support design meetings, customer visits and audits as necessary 

Candidate Profile

Essential:

• Significant experience in thermal engineering for semiconductor or system products, ideally within an AI/HPC chipmaker or advanced packaging environment. 
• Solid understanding of heat transfer and fluid dynamics, with experience in both air and liquid cooling solutions. 
• Experience with cooling technologies: heat sinks, vapor chambers, thermal interface materials, fans, pumps, valves, cold plates, manifolds, and CDUs. 
• Shown knowledge of system-level thermal integration, including interactions between die, package, substrate, heatsink/cold plate, and system chassis. 
• Experience collaborating with CEMs and managing supplier process qualifications. 
• Strong problem-solving skills, attention to detail, and ability to work multi-functionally in a fast-paced, global organization. 
• Proficiency in CFD tools (ANSYS, Icepak, FloTHERM) and CAD tools (Creo, AutoCAD, SolidWorks). 
• Strong communication skills in both English and Mandarin, with the ability to interface across global teams. 
• Degree in Mechanical Engineering, Thermal Engineering, or Materials Science, or equivalent experience. 

Desirable:

• Familiarity with rack-scale liquid cooling, immersion cooling, and energy efficiency standards (ASHRAE, ISO, Telcordia). 
• Knowledge of failure modes in liquid cooling (leakage, corrosion, pump life, coolant stability).