Two Phase Thermal Solution Guide
QUICK & EASY REFERENCE TO TWO PHASE THERMAL SOLUTIONS
1
Two-Phase Reference Guide
www.boydcorp.com
March 2021
Boyd Two Phase Thermal Solution Guide
A Quick & Easy Reference to Two Phase Cooling Technologies
Overview
Over several decades, Boyd has been a leading innovator of two phase cooling with superior solutions for everything
from consumer electronics to space applications. Boyd leveraged this experience and expertise to develop this Reference
Guide to help you understand two phase technologies and find the right solution for your applications. This article covers
the most popular two phase thermal solutions, integrations, and customizations as well as what to consider when
selecting the best technology for your application. Utilizing heat pipes, vapor chambers, or thermosiphons can be the
best way to optimize cooling with higher performance in more compact geometries for best total value.
CONTENTS
Two Phase Basics … 2
Quick Overview of how two phase cooling works & common categories
Core Technologies … 6
Heat Pipes
Vapor Chambers
Thermosiphons
Immersion Cooling
Design Considerations … 11
Wick Structures
Working Fluids
Materials
Next Steps … 13
Get started to find your ideal solution
Two Phase Thermal Solution Guide
QUICK & EASY REFERENCE TO TWO PHASE THERMAL SOLUTIONS
2
Two-Phase Reference Guide
www.boydcorp.com
November 2021
INTRODUCTION
As electronic designs demand more power, functionality, speed, and reliability, heat remains one of the major
barriers to maximize performance and realize major innovations. Every industry, especially Mobile, Medical,
Telecommunications, and IoT, is developing new applications that are lightweight, multi-functional, and high
power with increasing reliability standards. Engineers struggle to effectively handle excess heat as consumers
demand smaller, thinner, more powerful devices with more options and capabilities.
Two phase cooling is rapidly gaining popularity to solve
these issues. These technologies are especially ideal to
spread heat for faster dissipation, reduce weight, increase
reliability, and extend device lifetime, but their most
significant advantage is design flexibility and how easy and
efficiently they integrate in a system or device to vastly
improve cooling efficiency and capacity. Active air cooling
or liquid cooling systems are often too large, cumbersome,
and come with inherent complications such as unwanted
sound, heavy weight, and vibration. Two phase can replace
active cooling components and systems, not only solving
thermal challenges but also acoustic and vibration issues
for enhanced reliability.
While many engineers are most familiar with heat pipes, two phase cooling in a linear and very flexible form
factor, there are several major two phase technology types that
manage more heat and feature unique benefits and features. Vapor
chambers transfer heat in a planar geometry allowing for more
uniform heat spreading. Thermosiphons do not use a wicking
structure and can move more power by using gravity to return the
fluid. Meanwhile, Immersion Cooling is gaining popularity in cooling
high power components in markets such as data centers.
The following guide will touch on each of these technologies as well
as the benefits and considerations when utilizing them to cool your
applications.
Multi-technology Heat Pipe Assemble
Immersion Cooling Plate