Principle Thermal Mechanical Engineer

Flex (Flextronics)

Quick summary

Work type: On-site
Location: Littleton, MA
Salary: $153,500–$211,000 / yr
Posted: 8 days ago
Closes: Aug 28, 2026
Nearby: 99+ roles within 25 mi

Market check

Salary context

Above market

How this pay compares to similar roles

Similar $169k

This role $182k

$119k most similar roles pay here $221k

This role pays more than 66% of similar roles. Most pay $139,000–$198,400 — the shaded band above. At the midpoint, this role pays about $182k versus about $169k for comparable roles.

Based on 239 similar postings.

Employer

About Flex (Flextronics)

Flex (formerly Flextronics) is a global technology, supply chain, and manufacturing solutions provider helping companies design, build, and deliver products across industries. Industry: Electronics Manufacturing Services

Flex (Flextronics) currently has 15 open roles on FindRole.

Listed pay typically runs $126,500–$173,900 across 8 roles with salary data.

Most-posted roles

View all roles at Flex (Flextronics)

At a glance

TL;DR · Principle Thermal Mechanical Engineer

Apply Now Log in to save

The Principle Thermal Mechanical Engineer role is a senior position within the product development team at Littleton-based company, focusing on early-stage design and technical leadership for sustainable data center infrastructure solutions. This engineer will lead the conceptualization and detailed CAD design of complex fluid systems for liquid cooling, including cold plates and heat exchangers, while collaborating with customer teams to integrate these systems into broader product designs. Key responsibilities include conducting fluid flow simulations, performing thermal performance analysis, and developing engineering specifications that comply with industry standards. The ideal candidate has a Master's degree in Mechanical Engineering, at least 7 years of experience designing fluid systems, and proficiency in SolidWorks CAD, GD&T, and DFMs. They must also possess strong mentorship skills to guide junior engineers and contribute to the continuous development of cutting-edge thermal management technologies.

Skills

SolidWorks CAD GD&T DFM Fluid Dynamics Thermodynamics Heat Transfer Engineering Principles Simulation Software Ansys CFD MATLAB Python PostgreSQL Git Jira Confluence CI/CD AWS Kubernetes

What you'll do

Lead the design and optimization of complex liquid cooling systems from concept to detailed CAD.
Conduct fluid flow simulations and analyses to ensure efficient performance under various conditions.
Develop engineering specifications and documentation for fluid system components, ensuring compliance with standards.
Provide technical guidance and mentorship to junior engineers in mechanical design and thermal management.
Identify research needs and lead projects to maximize product impact and benefit.
Participate in design reviews, presenting technical findings and recommendations to stakeholders.

What we're looking for

Master's degree in Mechanical Engineering or related field with a thesis.
At least 7 years of experience designing and engineering fluid systems.
Minimum 3 years at senior or principal engineer level in an industrial setting.
Profound expertise in fluid dynamics, thermodynamics, and heat transfer principles.
Extensive SolidWorks CAD experience for complex part and assembly drawings.
Strong analytical skills with a track record of new product development.
Excellent communication skills to convey technical concepts to various audiences.

Similar roles

Principal Thermal Mechanical Engineer

Flex (Flextronics)

Littleton, MA 41 days ago $153,500–$211,000

Fluid Dynamics Thermodynamics Heat Transfer CAD ANSYS CFD SolidWorks AutoCAD Mechanical Design Pumps Tubing Heat Exchangers Data Center Thermal Management Coolant Distribution Units Simulation Software Validation Testing Technical Documentation Design Reviews Cross-Functional Collaboration Regulatory Compliance

Save

Thermal Engineer

Samsung Semiconductor

San Jose, CA 12 days ago $138,000–$206,000

FloTHERM CFD Heat Transfer Fluid Dynamics Thermal Simulation Technical Writing Verbal Communication IC Chip Design SiP Thermal Analysis Artificial Intelligence

Save

Sr. Thermal Systems Engineer

Flex (Flextronics)

Littleton, MA 36 days ago $126,500–$173,900

FloEFD Icepak MacroFlow ANSYS_Fluent COMSOL Python LabVIEW CFD DFX HALT HASS FMEA 8D PPS

Save

Principal Thermal Engineer

Oracle

US 40 days ago $109,200–$223,400

Direct-to-chip_liquid_cooling Cold_plate_cooling ASHRAE OCP RoHS Manufacturing_processes Supplier_management Technical_troubleshooting Process_audit Industry_standards Environmental_compliance Coolant_chemistries Test_plans Validation_results Process_control_documents Technical_reports CI/CD

Save

Senior Thermal Engineer

Anduril Industries

Costa Mesa, CA 12 days ago $146,000–$194,000

STAR-CCM+ ANSYS Icepak Flotherm SolidWorks Siemens NX CAD Python PostgreSQL CI/CD Git GitHub Docker Kubernetes AWS Azure Grafana Prometheus

Save

Senior Thermal Engineer

Anduril Industries

Huntsville, AL 12 days ago $126,000–$167,000

Abaqus Hero CHAR PATO ACE Mutation++ Thermodynamics Heat Transfer Fluid Mechanics Finite Element Analysis Computational Combustion Reacting Flows Material Properties Analysis Ablation Modeling

Save