PVD for decorative applications Lesson 3: The magnetron sputtering PVD process
Welcome to lesson 3 of the Ionbond Summer School!
Last time, we looked at the cathodic arc evaporation (CAE) technology in some depth. Today, we’re looking at the other main PVD technology for decorative coating: magnetron sputtering (MS).
The science behind sputter-based PVD
In basic sputtering, unlike with arc evaporation, the target material isn’t vaporized by an electrical arc but because ions with high kinetic energy slam into the surface of the target. On impact, these ions knock out the atoms required for the coating by momentum transfer. These atoms and atom clusters move in straight lines through the coating chamber and are deposited as a thin film on the substrate and chamber walls.
The role of magnetrons in sputtering technology
To increase the impact rates and the degree of ionization, the magnetron sputtering technology was invented. A permanent magnet is placed behind the target. Electrons in the plasma are directed onto a circular path by the permanent magnet and thus increase the ionization of the plasma. When that circular path, the plasma ring, intersects with the target material, that is where the vaporization happens preferentially. This results in the formation of a so-called sputter racetrack on the target, where the erosion of the target material is significantly stronger.
The advantages of magnetron sputtering
Coatings deposited by magnetron sputtering are:
Smooth
Highly adhesive
Homogeneous
Of high purity
Broad applications, smooth results
Due to the high energy of the impinging particles, the layers have a dense structure. Magnetron sputtering can be used to vaporize both electrically conductive and non-conductive materials. This makes it a very interesting technology for many applications, since the range of coating materials is large and many different coating properties and colors can be achieved.
Ionbond's decorative PVD coating solutions come in various colors
How material type shapes the sputtering approach
However, the technical approach is different for conductive and non-conductive materials. Electrically conductive cathode materials are mostly deposited using a direct current (DC) power supply. This isn’t possible for non-conductors: when a DC voltage is applied to these materials, the impinging charges cannot be dissipated. Instead, a counter-charge would build up, which counteracts the vaporization process. To vaporize electrically non-conductive materials, high-frequency (HF) power supplies (with a frequency of 13.56 MHz) can be used. The pulsed nature of these power supplies allows the built-up charge to dissipate in between pulses.
Ionbond PVD Operator at work
Boosting ionization for premium coatings
One drawback of MS is the naturally low ionization rate. In both the DC and HF processes, the degree of ionization of the plasma is less than 4%. 20 years ago, people started researching pulsed medium-frequency power supplies (20 - 350 kHz). These are now used widely in the industry.
The latest development in power supplies is high-power impulse magnetron sputtering (HiPIMS), which switches in the low frequency range (50 - 650 Hz). These power supplies give significant peak currents on the target, resulting in ionization degrees up to 80%, depending on the target material. This ionization rate is comparable to the CAE process, which means it is possible to reach comparable coating properties but without droplets and with significantly reduced roughness and defect density. However, HiPIMS technology has significantly lower deposition rates compared to CAE, so it is generally considered a premium option.
Curious if PVD is right for your application?
In these first three lessons, we’ve discussed how the different decorative PVD technologies work. In the next lesson, we’ll see how we can make these technologies work for us, by exploring the range of possible colors.
Whether you're working with metals, plastics, or ceramics, PVD coatings offer a wide range of possibilities in color, durability, and design. Before diving into the next lesson, why not connect with one of our experts? We’d be happy to explore how PVD can elevate your product and meet your specific needs.
Ron Dielis
Global Segment Manager Deco/Sports/Luxury
Ron Dielis
Global Segment Manager Deco/Sports/Luxury
Ionbond Summer School
Discover all our lessons on the fundamentals of PVD for decorative applications
PVD for decorative applications Lesson 1: Fundamentals of PVD
Available on 7. August 2025
Begin your Ionbond Summer School journey with the essentials of Physical Vapor Deposition (PVD). This lesson introduces the core phases: vaporization, transport, and deposition, that form the basis of decorative coatings, even on sensitive materials like plastics.
PVD for decorative applications Lesson 2: The cathodic arc evaporation PVD process
Available on 14. August 2025
Learn in lesson two how cathodic arc evaporation (CAE) works, why it’s the most energetic PVD process, and how it enables durable and decorative coatings.
PVD for decorative applications Lesson 3: The magnetron sputtering PVD process
Available on 21. August 2025
In Lesson 3, you'll explore magnetron sputtering: how it works, how it differs from CAE, and why it's ideal for smooth, high-quality PVD coatings.
PVD for decorative applications Lesson 4: Coating color range in decorative PVD
Available on 28. August 2025
This fourth lesson introduces hybrid PVD approaches using CAE and MS, showing how combining technologies enables decorative coatings with unique colors, durability, and performance. Discover Ionbond’s Coating Guide as a practical tool for selecting the right solution.