During the summer of 2023, I interned at Kelvin Thermal Technologies, a company specializing in ultra-thin, flexible phase-change cooling solutions.
As a manufacturing engineering intern, I contributed to the production of ultra-thin vapor chambers. Over the 12-week internship, I gained hands-on experience across the production lifecycle, participating in nearly every stage of the manufacturing process.
The TGPs consist of liquid and vapor substrates that undergo a series of production stages, including surface treatment and plasma processing, to prepare them for thermal bonding. Photos of these stages are shown on the right.
Background
A Kelvin Thermal TGP (Thermal Ground Plane) is a thin vapor chamber, essentially a 2D flat heat pipe, fabricated using flexible printed circuit (FPC)-compatible processes. It offers several advantages:
Low Cost
Ultra-Thin (0.15-0.25 mm thick)
Extremely Light (0.05-0.15 g/cm²)
Flexible (Bending radius between 10-3 mm)
High Thermal Conductivity (Ranges from 4,000 to 25,000 W/mK)
Unprocessed Vapor and Liquid Substrates, Respectively
The vapor and liquid substrates are first bonded to their respective casings, then bonded to each other to form a vapor chamber. The chamber is filled with a heat-transfer liquid, such as water. The liquid substrate contains tiny "pillars" that create precise flow channels for the fluid. As heat is absorbed, the water evaporates and moves to the vapor substrate, carrying the heat away. The vapor then condenses back into water through a wicking structure, allowing the cycle to repeat.
Contributions
I was involved in nearly all stages of TGP production, from general manufacturing to quality control. My specific contributions included:
Process Development: Worked alongside a mentor to support development of the assembly line and identify opportunities for process optimization.
Quality Control: Assisted with quality control inspections at each stage of production.
High-Volume Manufacturing: Produced vapor chambers on a weekly basis, using plasma processing and thermal cycling techniques.
Teamwork: Collaborated with a diverse group of interns from a range of backgrounds and skill sets.
Bonded Liquid and Vapor Substrate Casings
While there's more I could share about this experience, much of it remains confidential. Overall, this internship let me apply manufacturing principles from my coursework in a practical setting, working alongside a talented group of interns and engineers.
I also came away with a new appreciation for often-overlooked aspects of engineering, like quality control, which I now see as a critical step in product development.
