ALD particle coating with fluidized bed reactor (FBR)
We’ve talked about how atomic layer deposition (ALD) coating creates a strong, uniform, and pinhole-free barrier that protects even the most complex materials from corrosion and moisture. The same ALD coating method can also be used to coat materials such as fine powders.
And just to make sure that all readers are on the same page before we go further: when we talk about powder coating, it really means we coat the powder. We do not mean coating methods that use powder and electrostatic and thermal processes to replace conventional paint. That kind of powder coating is way too thick to be of any interest to us.
Coating fine powders
Fine powders are coated for multiple reasons - to improve their functionalization, to protect them from humidity and moisture, and to help prevent corrosion. Coating sensitive powders has helped industries such as LED lighting to improve product lifetime.
The best results for coating fine powders are achieved by ALD with fluidized bed reactor (FBR), as it’s the only reactor type that delivers conformal coating for single particles.
Why use a fluid bed and not a fixed bed? A fluid bed keeps the particles in motion. This allows for extensive mixing in all directions, and makes sure all particles are conformally coated.
A fixed bed basically keeps the particles stacked, leaving little to no room for the precursor gases to diffuse through the particle mass. This means that you’ll end up with particles that are partially coated, or not coated at all.
Illustration above: A fixed bed on the left, with stacked particles prevented from being conformally coated, and a fluid bed on the right, with fluidization enabling conformal coating of all particles.
The cross-section schematics above shows the Beneq ALD with FBR fluidization process (new features under patenting). Particles are kept fluid by a carrier gas and mechanical vibration. The residual gas analyzer (RGA) performs in-situ analysis, so you can see the results in real-time.
Watch Beneq FBR in motion
We developed the Beneq ALD with FBR module to keep particle mass fluid by using not one method, but two:
- By using gas flow through the reactor, and
- By vibrating the reactor module itself.
Watch Beneq ALD with FBR fluidization in action in this sand fluidization video clip.
We also designed observation windows in our FBR module so that you can observe the fluidization process. This is extremely useful when you’re setting the minimum fluidization flow, as it’s good to be able to see what’s happening. Once you’ve set the minimum fluidization velocity, it’s easy to scale up or down.
A stainless-steel reactor is also available for the high temperature depositions and production use. Both glass and stainless steel reactors can be used with the same FBR setup.
The picture above shows the Beneq ALD with FBR module with openings on two sides for easy observation. The module is also easy to remove and clean.
In addition to watching the fluidization, you can also see the actual results at the molecular level from the in-situ analysis provided by the residual gas analyzer (RGA). The RGA is integrated into the ALD system, which analyzes the results and provides real-time data on your PC.
In the chart above: residual gas analyzer (RGA) results of an ongoing fluidized-bed reactor (FBR) process. Beneq ALD with FBR.
Learn more about FBR, ALD, and us!
If you’re interested in learning about ALD, check our ALD Technology page.
If you are not familiar with Beneq TFS 200, you can find information here.
And if you would like to see (and hear) more from Beneq specialists give us a call or send us email!
Encapsulation of OLED microdisplaysBeneq developed a thin-film encapsulation nanolaminate coating for a leading Asian OLED microdisplay manufacturer to enable long lifetime for their microdisplays.
Insulator for thin film electroluminescent displaysAn ALD nanolaminate film was developed for Lumineq displays to create a fully pin-hole free thin film insulator layer.
Top electrode for transparent displayBeneq developed an ALD Transparent Conductive Oxide (TCO) for Lumineq's electroluminescent displays to replace the sputtered IDO that was used in the transparent top electrode.
Moisture protection of PCBsBeneq developed a low-temperature ALD moisture barrier solution for a leading supplier of electronics for personal safety monitoring to protect the sensitive circuit board components from moisture.
Encapsulation of phosphor powderBeneq provided a moisture barrier solution using ALD for FBR (fluidized-bed reactor) for a leading phosphor material manufacturer to protect the sensitive phosphor powders used in LED lighting from moisture.
Anti-corrosion coating for LED packagingBeneq's ALD coating solution solved a leading LED manufacturer's silver reflector corrosion problem by both applying ALD to coat the semi-finished wire-bonded LED assemblies, and by protecting the silver surface with nSilver.
Anti-reflection coating for solar glassBeneq and DSM created a production scale solution using DSM AR coating material and Beneq nFOG aerosol technology for a leading solar glass manufacturer to reduce light reflection on solar panels.
Metal-like coatings for watch partsBeneq developed a thin ALD-based optical coating for a leading watch parts manufacturer to both provide a specific color and to protect from corrosion.
Wafer-level moisture barrier for LEDBeneq provided moisture coating using TFS 200 for a leading LED manufacturer to protect LED dies from moisture and prevent oxidation.
Bottom DBR for LEDBeneq developed a multi-layer DBR structure on a patterned surface for a leading LED manufacturer.
Filling of diffractive gratingsBeneq used ALD coating to fill diffractive gratings for a leading optical system manufacturer to keep the gratings free from debris and boost their optical performance.
Anti-corrosion coating for sensorsThe highly conformal and pin-hole free ALD coating solved a leading sensor manufacturer's sensor corrosion problems without compromising sensor sensitivity.
Buffer layer for CIGS solar panelBeneq developed a thin, cadmium-free ALD buffer for the solar panels of a leading CGIS solar panel manufacturer.
Diffusion barrier for Li-ion batteriesBeneq's ultra-thin ALD coating solved a leading Li-ion battery manufacturer's battery corrosion challenges by reducing the fading of battery capacity caused by repeated charge and unload cycles.
Anti-tarnishing coating for jewelryBeneq helped Kalevala Jewelry in preventing the discoloration of silver surfaces by providing the patented nSilver industrial-scale protection solution for an ultra-thin, totally conformal, and fully transparent anti-tarnish coating.
Optical NIR filter on a glass cylinderBeneq developed a customized batch ALD process for a CCD sensor -based industrial vision systems supplier to coat their near-infrared (NIR) filters.
Optical coatings for lenses in high power lasersBenq developed a conformal high- and low-index multilayer optical coating for a leading provider of high power laser optics and coatings using the TFS 500 batch ALD system.
Coating of Microchannel Plates (MCP)Beneq developed an ALD coating solution for microchannel plates (MCP) for Incom, Inc., the world’s largest supplier of rigid fused fiber optics, to allow for significantly greater secondary electron emission .
Thin-film encapsulation of OLED lightingBeneq developed a conformal, dense, and pinhole-free Al2O3 and TiO2 barrier coating for a leading OLED lighting panel manufacturer to protect OLED panels from humidity.
Thin-film encapsulation of scintillator plates for X-ray imagingBeneq developed a conformal, dense, and pinhole-free low temperature Al2O3 and TiO2 barrier coating for a leading scintillator plate manufacturer to protect scintillator materials from moisture and increase product lifetime and reliability.