Other Applications

HFC-134a use in Magnesium Casting

Magnesium is a highly reactive metal. As temperatures of up to 800 °C can occur during the casting process, the surface of the melt has therefore to be protected against ignition, oxidation and the formation of nitrides. In the early years of industrial magnesium production only salt fluxes or powdered sulphur were known as protective cover for this purpose. To prevent contamination of the cast products, the salt fluxes were replaced by protective gas mixtures.

Sulphur dioxide (SO₂) was the first cover gas used in magnesium foundries to protect the molten metal and plays an important role still today. Due to its toxic and corrosive properties (especially humid SO₂ enhances corrosion of steel equipment) it was replaced by SF6 in most foundries. Due to its very high GWP SF6 was banned in the EU from 2018.

As well as SO₂ and dilute SO₂ mixtures, HFC-134a is being used as a cover gas. A study has shown that in die casting, on average 79% of the HFC-134a is destroyed over the melt during processing, reducing emissions of HFC-134a, and further reducing the environmental impact when compared to SF₆. For further information see the Öko-Recherche 2009 report for the European Commission.

Electronics Manufacturing Applications

While the EU CHIP Act drives expansion in semiconductor manufacturing, it’s important to recognize the indispensable role of fluorinated gases (F-gases) in achieving the high precision and quality demanded by this critical sector.

Exempted from quotas under the F-gas Regulation (EU) 2024/573 due to the lack of viable alternatives for key processes like plasma etching, F-gases enable the intricate fabrication of advanced microchips essential for Europe’s technological advancement.

Ongoing research and development efforts within the semiconductor industry are focused on optimizing F-gas usage, ensuring a balance between industrial progress and environmental considerations, without compromising the stringent requirements of chip production.

Electronics Manufacturing industries that use fluorocarbon gases for etching and chamber cleaning include liquid crystal displays (LCDs), photovoltaic cells (PV), and semiconductors (including light-emitting diodes). A range of gases are used in two important steps of electronics manufacturing:

plasma etching silicon containing materials and
cleaning chemical vapour deposition (CVD) tool chamber-walls where silicon has deposited.

The fluorinated gases used include CH₂F₂ (difluoromethane, HFC-32). The use of fluorocarbon gases in these processes is crucial to the production of devices, as there are no effective substitutes that can be utilized. Most FC emissions results from limited utilisation efficiency (i.e., consumption) of the FC precursors during the etching or the cleaning process. The state-of-the-art current solution to decrease GHG emissions from fluorinated gas usage is the implementation of abatement systems to contain and destroy residual gases.

The World Semiconductor Council (WSC) and its affiliated associations, agreed to voluntarily reduce atmospheric emissions of PFCs and information on the progress of this commitment was reported in a 2023 Statement of the 27th Meeting of the World Semiconductor Council (WSC) where the sector commits to further decrease PFCs emissions to 85% with the target year being 2030.