Chiller Technical Information　1-2. Fluorine-based inert liquids

This section describes the types, properties and main applications of fluorine-based inert liquids.

What is a fluorine-based inert liquid?

A generic term for organic solutions containing fluorine, it includes solutions such as perfluoropolyether (PFPE), perfluorocarbon (PFC), and hydrofluoroether (HFE).
Distributed products such as 3M’s FluorinertTM and Solvay’s Garden® have a high electrical insulation and are chemically inert and non-toxic, so they can be used for a variety of applications.

・Fluorinert^TM
A generic term for fluorine-based inert liquids manufactured by 3M. The basic structure is a perfluorocarbon (PFC). In addition to its high insulation performance, it has a high thermal conductivity and is therefore used as a cooling application for electrical devices.

・GARDEN®
A generic term for fluorine-based inert liquids manufactured by Solvay. The basic structure is a perfluoropolyether (PFPE). With a wide range of operating temperatures, they can be used even in high temperature environments of more than 200 °C depending on the form.

Properties of fluorine-based inert liquids

・High electrical insulation

・High density(1650～1900 [kg/m3])

・Low viscosity

・High thermal conductivity

・High thermal stability

・High chemical stability and inert

・Low toxicity and high safety due to non-flammability

Typical applications of fluorine-based inert liquids

Due to the properties above, fluorine-based inert liquids are used in many applications but some of the typical applications are introduced here.

(1) Airtightness test

To prevent infiltration by moisture and electrical reaction of the chip, electronic devices need to have a fully sealed structure. Fluorine-based inert liquids have a low viscosity and besides being excellent for evaluating airtightness, they are also inert, so they will not corrode or alter electronic components.

(2) Solvents and cleaning agents

Fluorine-based inert liquids have a low surface tension and viscosity, allowing them to penetrate even small gaps to wash every corner. It is used for degreasing and cleaning after product processing.

(3) Cooling

Direct immersion cooling

Fluorine-based inert liquids have a high thermal conductivity and are characterized by their electrical insulation and inert properties, allowing electronic devices to be immersed directly into them for cooling. This is much more efficient compared to air-cooled electronic devices and can significantly reduce the installation space and power consumption required for cooling.
Example) Liquid immersion cooling of servers
It is said that more than 100 trillion sensors will be connected to the Internet by the year 2030, resulting in a huge amount of data being collected. Instead of conventional air cooling, the entire device is immersed in a liquid to cool it down and reduce energy consumption, enabling efficient cooling without having to use a vast space. In recent years, the technology has continued to improve significantly, and in some cases this cooling method has also been introduced to cool down supercomputers that are growing in capacity.

Indirect circulatory cooling

A fluorine-based inert liquid is circulated while keeping the temperature constant with a heat exchanger, indirectly keeping the object at a constant temperature. Due to the high insulation performance, it is easy to maintain and highly effective in preventing electric corrosion. Due to its non-flammability and high safety, it is also suitable for cooling equipment in clean rooms.
Example) Temperature control of various semiconductor manufacturing equipment
Exposure equipment, dry etching equipment (electrode), sputtering equipment, CVD equipment, etc.
With its excellent electrical insulation and improved maintainability, it can accommodate a wide range of temperatures, from ultra-low to high temperatures.

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