Clean Dry Air
The air quality levels that are needed in this sector go way beyond those of most other applications. There is hardly any other industry where contamination can have such critical and expensive consequences.
In addition, while some applications require oil-free, dust-free or dry compressed air, in the semiconductor industry, it has to be all three. That is because any moisture, particulates/dust or oil in its cleanroom can ruin an entire batch of semiconductors and, more importantly, the stainless steel components of the machines producing them.
This can cost millions of euros and dollars. Therefore, air quality is essential, and a reliable supply of clean dry air is crucial.
Building an optimal CDA system
It all starts with achieving the highest air quality. The quality of compressed air is categorized by an international standard called ISO 8573-1:2010. It determines how much of any given contaminant the air can contain to be clean enough for different applications.
In a cleanroom environment, the air quality has to be extremely high. Therefore, the ISO standard is divided into seven classes and three contaminants – moisture, oil, and particulates. To get there, you need a top-quality clean dry air system to protect your cleanroom and your semiconductor production. That starts with a clean dry air compressor. The lower the class, the cleaner the air. Compressed air that is extremely dry and contains no traces of oil or particles would be Class 0 dry air for all three contaminants. Most applications don’t need to reach Class 0. And if they do, then the air either has to be oil-free, water-free or particulate-free, but rarely all three.
In the electronics industry, however, the air needs to be all of the above to avoid production shutdowns and product contamination. That means, in order to meet CDA quality, it has to achieve Class 0 for all contaminants.
Oil
You require an oil-free compressor to achieve that first zero. Atlas Copco offers a wide range of models that supply you with oil-free air reliably and efficiently. This ensures that your semiconductor batches don’t get contaminated and your machinery doesn’t get ruined because of corrosion, you can also lower your production costs.
Water
Because the air has to be completely dry for semiconductor production, you need a CSD desiccant (or adsorption) air dryer. That is the only way to reach the required pressure dew point (PDP) of below -70°C. Here, too, we have a complete range of solutions. This includes dryers with Cerades™, the first solid compressed air desiccant.
Particulates
To achieve dust-free air, you need various clean dry air filters. The first is placed between the compressor and the dryer. That protects the dryer. The others are installed downstream from the dryer and include a PTFE membrane filter. Together, they eliminate particles down to a size of 0.01 μm. We also meet all of your filtration needs.
Manufacturer saves $16000/yr with Optimizer 4.0
A semiconductor manufacturer's compressor room was suffering from inefficient sequencing. They had a compressor room with seven compressors monitored by an ES16 Central Controller. The inefficient sequencing was a result of frequent communication losses between the Central Controller and the compressors.
Challenge
The Atlas Copco team visited the site and conducted a track study to analyze the compressor’s operating pattern and the efficiency of the existing ES16 Central Controller. As such, the data revealed an annual energy loss of 77 MWh (77 000 kWh) due to unloaded energy inefficiencies.
Solution
The existing Central Controller was replaced with our Optimizer 4.0 Central Controller which offers enhanced software support and algorithms which automatically determine the optimal combination of machines. This reduced both loaded and unloaded hours, improving efficiency.
Outcome
The energy consumption in unloaded state dropped from 77 000 kWh per year to just 800 kWh per year, representing a 99% reduction. Thanks to the new Optimizer 4.0, annual energy savings of more than 76 000 kWh were achieved, which is equal to USD 16 000 per year. Additionally, this improvement resulted in a CO₂ emissions reduction of 31 tons per year.
ZR ZT (VSD)
With either oil-free compressor, your processes and products are protected by clean air, with no contamination originating from the compressor. The ZR is water-cooled, and the ZT is air-cooled.
With pressure levels ranging from 3.5 up to 13 bar, we maximize your energy savings with our rotary screw technologies. This all-in-one quality air solution is available as Full Feature package with integrated dryer and variable speed drive (VSD).
ZH+
The centrifugal oil-free air compressor ZH+ comes as a complete packaged solution with:
▸efficient inlet silencer and filter
▸integrated blow-off valve and silencer
▸mounted cooling water manifold
▸sound attenuating canopy
Combine the ZH+ with the regulating capabilities of the ZR VSD for maximum energy efficiency.
MDG dryer
The MDG heat of compression dryer is the world’s first dryer that provides a stable and guaranteed Pressure Dew Point (PDP) of -40°C (-40°F) at near zero power consumption.
The unit has no heating element, no blower and there is no loss of compressed air (purge). Its total power consumption is always below 120W. Compared to market standard desiccant dryers, the MDG’s operational cost is close to zero - even at high electricity costs.
Applications - across the value chain
Cooling air
Cooling of products in the clean room is the most critical clean air application in electronic plants.
Clean room
Contaminants must be eliminated and the temperature and humidity controlled. So the compressed air must be class 0 oil-free.
Patterning
In patterning (photolithography), a specific pattern is imprinted on the wafer. Clean, dry air is needed here for pattern uniformity.
Instrumentation
Oil-free air prevents contamination during sorting, packaging, testing, handling, assembling, etching. instrumentation or pneumatic applications.
Purging
The purging of the vacuum and venturi pumps have to be done with oil-free air to avoid contamination.
FAQs
How clean and dry does the air have to be?
It has to meet Class 0 of ISO 8573-1:2010, which is the international standard for air quality classes.
This standard defines how much of any of the three contaminant types the air may contain. The lower the class, the higher the quality of the air. Therefore, Class 0 means the least-contaminated air can be.
And to meet the requirements of a cleanroom in semiconductor production, the air should achieve Class 0 quality for moisture, oil, and for dust.
How do facilities acheive Class 0 for moisture, oil and dust?
- It all starts with the right air compressor. An investment in an oil-free unit means that there is already one contaminant semiconductor producers no longer have to worry about.
- Next, special filters remove dust or other particles from the compressed air and keep them out of cleanrooms. You will need several of them to get to Class 0.
That takes care of the “clean,” but what about the “dry?” that will eliminate the risk of corrosion?”
- For that, you will need a high-performance dryer that can reach a pressure dew point (PDP) below -70°C. This kind of PDP can be achieved with a desiccant adsorption dryer. These desiccant dryers are the optimal choice for providing very dry air for critical applications.
How is a typical CDA installation set up to keep contaminants out of the cleanroom?
- First comes the oil-free compressor. Because the production of semiconductors requires a lot of energy, it makes sense to invest in an energy-efficient model. That can greatly lower operating costs.
- Next comes a pre-filter. Its job is to catch most of the particles in the compressed air. That way, the air that reaches the dryer is already much cleaner, which helps reduce its maintenance needs. While an adsorption dryer does a great job of drying the air, it may produce some desiccant dust. Therefore, the newly dried air is then routed through two after filters. They filter out the desiccant dust and further purify the air.
- At this stage, only the tiniest particles are left. Now, the air merely has to go through one more filter. Usually, this is a PTFE membrane filter that utilizes surface filtration technology to capture particles down to a size of 0.01 μm.
Following that final step, the clean dry air can now be used in a cleanroom environment without jeopardizing the semiconductor production.