Staff/Principal Thermal Engineer

Staff/Principal Thermal Engineer

About the Company

Xscape Photonics is a cutting-edge technology company developing advanced photonic systems for high-

performance computing and communication applications. Our work focuses on enabling next-generation

optical interconnects through innovative integration of photonics, electronics, and packaging technologies.

We are building highly efficient, scalable solutions where thermal management plays a critical role in

performance, reliability, and product success.

We are seeking a Staff or Principal Thermal Engineer to own thermal architecture, performance, and

strategy for our photonic and electronic systems - from early concept through production. This is a high-

ownership role: you will set the thermal design direction across programs, own module thermal

performance against target temperature and crosstalk limits, lead the development of cooling solutions

(TECs, TIMs, heat spreaders/heat sinks, air and liquid cooling), drive simulation and validation

methodology, and own thermal-related failure analysis. You will represent thermal engineering in

customer- and leadership-facing technical reviews, work closely with optical, mechanical, electrical,

packaging, firmware, and reliability engineers, and mentor and guide other thermal engineers as the team

scales.

Key Responsibilities

Thermal Design & Analysis

• Own thermal architecture and strategy for photonic modules and systems across multiple

programs, from concept through production

• Lead design and development of cooling solutions using:
• Thermoelectric coolers (TECs)
• Thermal interface materials (TIMs)
• Heat spreaders and heat sinks
• Air cooling and liquid cooling approaches
• Perform thermal trade-off analysis across candidate designs, evaluating cost, power

consumption, and mechanical and electrical complexity to guide architecture decisions

• Lead critical cooling-technology, material, and supplier decisions (TECs, TIMs, cooling solutions),

balancing product performance, cost structure, and long-term scalability

• Set thermal simulation methodology and standards; drive CFD analysis strategy (temperature

distribution, heat flow, thermal crosstalk) and review the work of other engineers

• Define and own the thermal test and validation strategy, including instrumentation

(thermocouples, IR imaging, DAQ/LabVIEW) and test-to-simulation correlation

Thermal Failure Analysis

• Own thermal-related failure analysis, working closely with the Lead FA Engineer on the overall FA

process

• Diagnose thermal-stack failure modes such as TIM pump-out and dry-out, solder void growth,

bond-line degradation, TEC fatigue over thermal cycling, and warpage-driven loss of contact

• Apply thermal FA diagnostic techniques - IR/lock-in thermography for hot-spot localization,

thermal transient testing and structure-function analysis, and coordination of CT/acoustic

microscopy for interface defect detection

• Feed FA findings back into design margin, TIM/material selection, and thermal qualification

criteria to prevent recurrence

Cross-Functional Leadership

• Own accountability for module thermal performance against targets - define the thermal budget,

junction and case temperature limits, TEC/laser operating windows, and allowable thermal

crosstalk, and hold the design to them from prototype through production and across the

product & operating life

• Own thermal integrity of the system, including thermal runaway prevention, heat-path

optimization, and definition and enforcement of worst-case operating margins and guard-bands

across environmental and use-case variations

• Represent thermal engineering in customer and executive/leadership reviews; present thermal

compliance, risk, and trade-offs at program milestones

• Partner with mechanical, PCB, and packaging engineering to integrate thermal requirements

early in design

• Support new product introduction (NPI) and transfer to manufacturing, including design for

manufacturability and production ramp - working with contract manufacturers and assembly

teams on TIM application, reflow, and thermal-stack assembly processes to ensure thermal

performance holds in volume production

• Mentor and provide technical guidance to junior and mid-level thermal engineers; may directly or

indirectly lead a small thermal team as it scales

• Own thermal risk assessment, design reviews, and technical documentation across programs

Required Qualifications

• Masters or PhD in Mechanical Engineering, Aerospace Engineering, or a related field, with a

focus on heat transfer and fluid mechanics

• 8+ years of thermal engineering experience for Staff, or 12+ years for Principal (PhD + 5+ years

of industry experience may be considered equivalent to MS + 8+ years for Staff-level scope)

• Demonstrated track record designing and delivering cooling solutions using TECs, TIMs, heat

spreaders/heat sinks, and air and liquid cooling

• Deep CFD simulation expertise (e.g., Ansys Icepak/Fluent, Ansys Mechanical, or equivalent) with

a record of setting simulation strategy, not only executing models

• Extensive hands-on thermal test and validation experience (IR imaging, thermocouples, DAQ

systems) with demonstrated test-to-simulation correlation

• Demonstrated root-cause problem solving and thermal failure analysis, including experience

diagnosing thermal-stack failure modes and applying thermal diagnostic techniques (e.g., IR/lock-

in thermography, thermal transient testing)

• Experience owning thermal architecture at the system or program level, not solely at the

component level

• Strong teamwork and cross-functional collaboration skills, with the ability to work effectively

alongside optical, mechanical, electrical, packaging, firmware, and reliability engineers

• Excellent written and verbal communication skills, including the ability to present complex thermal

analyses and trade-offs clearly to both technical and non-technical audiences

• This is a full-time, on-site role based in Santa Clara, CA

Preferred Skills

• Experience in photonics, optical transceivers, or high-density electronics packaging
• Experience with vapor chamber thermal design for high power-density, space-constrained

applications

• Experience presenting thermal compliance and risk directly to customers or executive leadership
• Prior mentorship or direct/indirect leadership of other thermal engineers
• Programming and data analysis skills (Python, MATLAB) for test automation and data processing
• Experience with qualification/certification test campaigns and thermal reliability of materials and

interfaces

What We Offer

• Ownership of thermal strategy on advanced photonics systems at the ground floor of a fast-

scaling startup

• Collaborative and innovative work environment with direct access to leadership
• Competitive salary, equity, and benefits
• Career growth in a rapidly evolving technology space