ALD CAP
ALD-CAP®
Exceptional Barrier Performance
ALD-Cap® is a flexible ceramic coating with exceptional barrier performance due to the pin-hole free and low stress nature of the atomic layer deposition (ALD) films used. ALD lays down films one atomic layer at a time. The films are inherently uniform, pin-hole free and virtually 100% conformal to the substrate surface. The physical properties of ALD-Cap® are summarized in the table below.
The extremely low permeability levels allow for efficient protection of environmentally sensitive devices, such as organic light emitting diodes (OLED) and solar photovoltaics. For comparison, water vapor transmission rates (WVTR) for OLED must be < 10-6 g/m2/day, and oxygen transmission rates (OTR) must be < 10-3 cm3/m2/day. For Organic Photovoltaics, the required WVTR is at the high level of 10-5 g/m2/day. These transmission rates are several orders of magnitude smaller than what is possible using any polymer-based coatings as the table indicates. Forge Nano has partnered with leading suppliers for OLED and solar barrier films to use ALD-Cap® as a barrier for these applications. Property | ALD-Cap | Parylene C | Urethane |
Hardness (GPa) | 8-10 | 0.13 | <<0.13 |
Young’s Modulus (GPa) | 130-180 | 2.8-3.2 | 1.5 |
Elongation to Failure (%) | 100-300 | 200 | 250 |
Density g/cm3 | 3-5 | 1.29 | 0.9-1.2 |
Index of Refraction | 1.55-1.75 | 1.639 | 1.5-1.6 |
Dielectric Constant (DC) | 6-9 | 3.15 | 3.5 |
Dielectric strength (MV/cm) | >8 | 2.2-2.8 | 1.4 |
The Premier Environmental Protection Coating
ALD-Cap® provides exceptional performance for many applications requiring the highest level of environmental protection. For example, high reliability electronic components coated with ALD-Cap® demonstrated hermetic performance that passes MIL-STD 883E environmental endurance testing with total thickness as low as 200 nm.
This allowed use for the first time of non-hermetic off-the-shelf packaging in electronic systems deployed in radar systems for Navy ships.
As a versatile, non-invasive add-on, ALD-Cap® can be used at different stages of the IC or electronic assembly. It can be applied at the wafer-level, replacing SiN-cap passivation, as well as at the die or the package level. If needed, ALD-Cap can also be implemented in combination with thicker conformal films for added ruggedness. The atomic level control of film composition offered by the ALD technique allows for tailoring specific adhesion layers to different substrates. This yields consistent high adhesion to various materials with adhesion often comparable to the adhesion strength of galvanized zinc to steel, as shown in the table below. Substrate | Application | Coating Adhesion |
Pull Strength (PSI) | ||
Immersion Tin | PCB Finish | 1,700 |
Bright Electroplated Tin | PCB Finish | >1,500 |
Gold | PCB and Package Finish | >1,400 |
Copper | Many | >1,600 |
Monel | Pressure Sensor | >2,000 |
PET (FOLED Grade) | FOLED Substrate | >1,200 |
PEN (FOLED Grade) | FOLED Substrate | >1,250 |
Lexan | Many | >1,400 |
Kepton | Many | 1,000 |
FR4 | PCB Material | >2,5000 |
R/Flex | PCB Material | 1,200 |
Thermosetting Epoxy | PEM Package Material | >2,500 |
3M Scotch-weld 2216 B/A | IC Attachment | >3,300 |
17-4 Stainless Steel | Medical Surgical Tools | 1,750 |
Titanium | Medical Implants | 1,500 |
Glass | Many | >2,000 |
Nanolamination for Optimal Performance
The typical structure of ALD-Cap® is a nanolamination of Al2O3/TiO2 layers capped with a TiAlO composite corrosion protection layer, as the SEM cross-section below shows. Many other alternative combinations can be used such as Al2O3, Al2O3/TiO2 lamination, Al2O3/SiO2 lamination, Al2O3/ZnO. Corrosion protective alternatives have been SiO2, BN and AlBNO. Actual composition and layout is determined based on performance.
Our ALD-Cap® process allows for easy optimization of film recipes with excellent repeatability and with no need to re-optimize the process. For example, any desired combinations of Al2O3/TiO2 lamination can be written into a recipe and executed to perfection once the parameters of the Al2O3 and TiO2 processes are defined. If adhesion promotion is needed, a thin interface layer of 1-2 nm of other materials can be added.
Fig. 1: FIB-cut SEM image shows the layer structure of a CCA (circuit card assembly) coated with 250 nm ALD-Cap.
High Productivity Process
Our ALD process is performed at low temperatures (down to 80° C) and at high deposition rates of 12 nm/min. Films in the range of 200-500 nm are required for demanding applications such as OLED protection and are regularly used. Forge Nano’s SMFD-ALD patented equipment incorporates proprietary innovations that deliver high deposition rates at maintenance intervals longer than 350 μm accumulated film. This unique capability achieves high productivity at the lowest cost of ownership. Forge Nano’s production equipment line currently includes fully automatic cassette-to-cassette wafer equipment, as well as industrial coaters for parts and components.
About Forge Nano
Forge Nano is a leading materials science company harnessing the power of Atomic Armor, the company’s proprietary ALD nanocoating technology, to accelerate manufacturing innovation, transform product performance and achieve a more sustainable future for a range of industries around the world. Atomic Armor produces superior coatings that can unlock a material’s performance at the atomic level and deliver custom solutions from small-scale R&D and laboratory work to large-scale, high-volume production lines. A range of materials can be enhanced through Atomic Armor, including batteries, medical devices, catalysts, propellants and 3D additives. Forge Nano has received major support and signed meaningful partnerships with Volkswagen, LG Technology Ventures, Mitsui Kinzoku, Air Liquide and Sumitomo Corporation of Americas, largely as a result of the company’s innovation in the Lithium-ion battery industry and successful track record of improving product performance and safety while reducing cost.
Forge Nano’s Capabilities
- >20 in-house ALD systems for coating of wafers, powders and objects
- Including research, pilot and commercial scale systems capable of processing anywhere from 1.0 g to 30,000 kg powder or extrudates per day
- Fast deposition times up to 30nm per minute for rapid Al2O3 ALD coating solutions
- The world’s most knowledgeable and experienced team for ALD onto a range of materials
- PhD scientists, certified Professional Engineers, career scientists
- 20+ years’ experience designing and building powder ALD systems
Working with Forge Nano
Forge Nano assists customers daily with both R&D and commercialization of ALD-enabled materials. For R&D, we offer research services for proofs of concept and also sell our R&D equipment globally. For commercialization, we offer joint development of products, production equipment and IP licensing.