Cleanroom grade standards 

The grades of cleanrooms are usually divided according to the number and size of particles allowed in the air. Internationally, ISO 14644 is usually used for grade classification. According to this standard, the grades of cleanrooms are from high to low: ISO 1-9.

It should be noted that cleanroom standards can vary depending on the specific industry and application. In semiconductor chip production, cleanroom standards are usually more stringent to ensure that the quality and performance of the chips produced meet expectations.

Cleanroom levels can be divided into: Class 1 > Class 10 > Class 100 > Class 1000 > Class 10000 > Class 100000 > Class 300000.

Class 1 cleanrooms are mainly used in the microelectronics industry for manufacturing integrated circuits, and the precision requirements for integrated circuits are submicron.

Class 10 cleanrooms are mainly used in the semiconductor industry with a bandwidth of less than 2 microns.

Class 100 cleanliness is widely applicable and can meet the cleanliness needs of most industries. It can be used for aseptic manufacturing technology in the pharmaceutical industry. This cleanroom can be used for surgery for the manufacture of transplants and integrators, as well as isolation treatment of patients who are particularly sensitive to bacterial infections.

Class 1000 cleanrooms are mainly used for the production of fine optical products, and are also used for testing, assembly of aircraft gyroscopes, assembly of fine micro bearings, etc.

Class 10000 cleanrooms can be used for the assembly of hydraulic equipment or pneumatic equipment, and in some cases are also used in the food and beverage industry. In addition, Class 10000 cleanrooms are also widely used in the medical industry.

The permissible particle concentration of 0.5um in a Class 1000 clean room is less than 35200 (pc/m3), and the permissible particle concentration of 5um is less than 293 (pc/m3). 2. The permissible particle concentration of 0.5um in a Class 10,000 clean room is less than 352000 (pc/m3), and the permissible particle concentration of 5um is less than 2930 (pc/m3).

 Safety considerations 

The decoration of semiconductor cleanrooms must meet safety requirements. Generally speaking, there are a large number of flammable and explosive substances in semiconductor cleanrooms, so the relevant national safety regulations, such as fire prevention and explosion prevention, should be followed during decoration. In addition, environmental pollution and the health and safety of staff should also be considered to ensure that the decoration materials meet national standards and will not cause harm to human health.

 Cleanroom air treatment system 

Semiconductor cleanrooms require air treatment systems to ensure the cleanliness of the air in the workshop. The air treatment system is mainly composed of air filters, air supply systems, return air systems and exhaust systems. Among them, air filters are an important component that can effectively remove particulate matter and microorganisms in the air.

 Floor, wall and ceiling decoration 

In the decoration of semiconductor cleanrooms, the decoration of floors, walls and ceilings is very important because these areas are susceptible to pollution. The floor should be made of wear-resistant, anti-static and easy-to-clean materials, such as Epoxy self-leveling floor or PVC plastic floor; the walls and ceilings should be made of corrosion-resistant, anti-static and easy-to-clean materials, such as aluminum plates, stainless steel plates, glass curtain walls, etc.

 Layout of electrical equipment such as lamps and sockets 

In the decoration of semiconductor cleanrooms, the layout of lamps and sockets is also very important. In order to prevent pollutants such as dust and microorganisms from entering the workshop, these devices should be installed on the ceiling or above the wall height, and anti-static and non-powder-shedding materials should be selected.

 Doors, windows, clean workbenches and other facilities 

In the decoration of semiconductor cleanrooms, doors, windows, clean workbenches and other facilities also need special consideration. Doors and windows must be made of materials with good sealing performance and easy to clean, such as stainless steel doors and windows; clean workbenches should be made of materials that do not shed powder, slag particles, are corrosion-resistant and easy to clean, such as stainless steel workbenches.

The electronic chip clean room is a special industrial building designed to effectively control key parameters such as air particle concentration, microbial count, temperature and humidity, air flow speed and air pressure in the workshop. The precise control of these conditions ensures the smooth progress of the production process and the high standard of product quality to meet the strict requirements of electronic chip manufacturing.

 1. Equipment selection 

 1. Air treatment equipment 

Air treatment equipment is one of the key factors in maintaining the cleanliness of the workshop. Its main function is to filter and purify pollutants in the workshop, and at the same time adjust parameters such as temperature, humidity and air pressure in the workshop to meet the requirements of production process and product quality.

 2. Air shower room 

The air shower room is an important equipment in the clean workshop, which is mainly used to remove dust, sterilize and purify personnel, materials and equipment entering the workshop. The electronic chip clean workshop should be equipped with an air shower room to reduce the entry of external dust, microorganisms and other pollutants into the workshop. The size and number of air shower rooms should be designed according to the actual situation of the workshop to ensure that it can meet the cleanliness requirements of the workshop.

 3. Clean room dressing room 

The clean room dressing room is an isolation area inside and outside the clean room. The staff needs to wear clean clothes, gloves, shoe covers and other protective equipment in this area to ensure that the personnel entering the clean room will not bring in external pollutants.

 4. Air shower 

The air shower is used to perform air showers on personnel entering the clean room to remove particles and bacteria that may be carried by the personnel and ensure the cleanliness of the workshop.

 5. Air purifier 

The air purifier can purify pollutants such as dust, bacteria, viruses, etc. in the workshop air to ensure the cleanliness of the workshop.

 6. Temperature and humidity control system 

The temperature and humidity control system can control parameters such as temperature, humidity and air pressure in the workshop to ensure that the workshop environment meets the requirements of production process and product quality.

 2. HVAC system 

 1. Air conditioning system 

The air conditioning system is the main HVAC equipment in the electronic chip clean workshop. Its function is to adjust parameters such as workshop temperature, humidity and air flow speed to maintain the cleanliness and comfort of the workshop.

 2. Air supply system 

The air supply system sends clean air from the air conditioning equipment into the workshop to form a relatively static air flow layer to maintain the cleanliness of the workshop.

 3. Exhaust system 

The exhaust system of the electronic chip clean workshop is one of the key equipment of the entire workshop. Its function is to exhaust pollutants in the workshop and maintain the cleanliness of the workshop.

At present, there are two main types of exhaust systems in the electronic chip clean workshop, namely local exhaust systems and global exhaust systems. The local exhaust system uses a single device to exhaust local process equipment, which can achieve higher air volume and static pressure, and is suitable for workshops with higher requirements for air cleanliness. The global exhaust system includes the entire workshop in the exhaust range, which is mainly used in occasions where the requirements for workshop temperature, humidity and cleanliness are not very high.

 3. Decoration materials 

When choosing decoration materials for electronic chip clean workshops, it is necessary to consider their impact on the clean environment, and also ensure that they have anti-static capabilities. It is recommended to choose anti-static floors, walls, ceilings and other materials.

For the corners of walls and floors, arc designs should be used to reduce dust accumulation.

 4. Lighting design 

In the lighting design of electronic chip clean workshops, lighting equipment with anti-static functions should be selected. It is recommended to use cold light sources or LED lamps to reduce heat radiation and heat dissipation. At the same time, it is also necessary to consider the uniformity and brightness of lighting to meet work needs.

 5. Waste gas and wastewater treatment system 

During the production process of the electronic chip clean workshop, a large amount of waste gas and wastewater will be generated. In order to ensure the cleanliness of the environment and ecological protection, a corresponding waste gas and wastewater treatment system must be configured. The waste gas treatment system mainly includes the exhaust system and the tail gas treatment system, and the wastewater treatment system mainly includes the sewage collection, pretreatment and treatment system.

 6. Pure water system 

A large amount of pure water is required in the production process of the electronic chip clean workshop, so a pure water system needs to be configured. The pure water system should include a pre-treatment system and a purification system to ensure that the supplied pure water can meet the production requirements of the workshop.

 7. Gas supply system 

A large amount of nitrogen, hydrogen and other gases are required in the production process of the electronic chip clean workshop, so a corresponding gas supply system needs to be configured. The gas supply system should include gas storage tanks, gas filtration, gas drying and other equipment to ensure the quality and stability of the supplied gas.

From September 4 to 7, 2024, the 14th Bangkok RHVAC, a biennial event, hold at the Bangkok International Trade and Exhibition Center. At that time, KLC presented HVAC series of Air filter and Equipment products at the exhibition.

The successful holding of the 2024 Bangkok RHVAC is not only a collision and integration of technical exchanges and cooperation, but also an in-depth exploration of future development trends. KLC is an air filter and air purification equipment enterprise intergrating R&D, production and sales to provide comprehensive and advanced clean air solutions and services for industries all over the world, and jointly promote the high-quality development of the refrigeration industry.

At the exhibition, KLC attracted the attention of many customers and partners with its innovative air filtration products and solutions. KLC business personnel combined on-site exhibits and video demonstrations to allow visitors to have a deep understanding of the application and installation of the filtration system.

The Bangkok RHVAC+E&E 2024 exhibition provides new opportunities for the future development of KLC. KLC will continue to be committed to technological innovation and market expansion to meet the growing needs of customers. We look forward to exploring the cutting-edge trends of the industry with more colleagues in the industry at future exhibitions, and jointly promoting progress in the field of HVAC! Thank you to all customers and partners who visited our booth, and thank you for your attention and trust in KLC.

Dear customers and partners,

We sincerely invite you to attend the upcoming RHVAC 2024 exhibition in Bangkok! As a professional filter and cleanroom solution provider, we will showcase our latest air purification products to help you create a dust-free environment and improve the cleanliness of your workplace.

 Exhibition information: 

 Date:  4-7 SEP 2024

 Location:   EH 98-100 BITEC,BANGKOK THAILAND

At this exhibition, we will show how to help various industries achieve stricter cleanliness standards through innovative and efficient filtration systems. We look forward to sharing our expertise with you and discussing how to provide customized solutions for your business.

Please arrange time to visit our booth and communicate with our team in depth. Looking forward to seeing you at the exhibition and moving towards a cleaner future together!

Best wishes

From November 12 to 14, 2024, the KLC team participated in the highly anticipated FILTECH exhibition in Cologne, Germany. As an important event in the field of global filtration and separation technology, this exhibition attracted industry leaders, experts and innovation pioneers from all over the world to gather together to discuss the latest technological developments and market trends of filtration equipment.

During the three-day exhibition, KLC displayed the latest products and solutions in the field of filtration technology such as AC FFU, high temperature Separator Filter, and high frequency bag filters. The KLC booth attracted the attention of many visitors, and the attendees showed great interest in our innovative technologies.

FILTECH is a global event and platform that focuses on the filtration industry and adjacent sectors. It is the largest and most significant event of its kind worldwide, showcasing the latest technological advancements and innovations in the field of filtration and separation. FILTECH brings together experts, researchers, and industry professionals from various sectors to address pressing issues such as air pollution, climate impact, health hazards posed by germs, and optimizing efficiency in solid and liquid separation processes. From technologies for air filtration to solutions for solid and liquid separation, FILTECH offers tailored solutions to meet the diverse needs of industries across the board. It provides a platform to explore targeted solutions for all filtration challenges, driving progress and excellence in filtration and separation technologies.

The FILTECH exhibition provides us with an important platform to understand industry trends. By participating in multiple technical forums and seminars, we have obtained valuable information on the latest research results and development directions of filtration and separation technology. These insights will help KLC maintain a competitive advantage in future product development and market strategy.

Overall, KLC's experience of participating in the 2024 FILTECH exhibition was extremely successful. We not only demonstrated the company's technical strength, but also strengthened our connections with all parties in the industry. Thank you to all friends who visited our booth, and look forward to jointly promoting the development of filtration and separation technology in future cooperation. We look forward to seeing you again at the next exhibition and exploring more possibilities together!

High-efficiency air outlets are ideal terminal filtration devices and are widely used in the pharmaceutical, health, electronics, chemical and other industries. In order to verify whether the clean room can meet the cleanliness requirements, it is necessary to test the clean room and high-efficiency air outlets, so its detection is very important.

 How to measure the air volume of high-efficiency air outlets: 

1. You can use the air volume hood to directly aim at the nozzle for one-time measurement. Since your nozzle has many small holes (to make the air volume uniform) and there is a grille, then your anemometer can be kept 3-5 cm away from the nozzle. If you have a thermal anemometer, try to face the gap instead of the grille, and measure the average value by the grid method. The same cross-section can be measured.

2. You can measure at multiple points at a distance of 2 times the width of the diffuser from the air outlet. The measuring points should be like a grid and then the wind speed is averaged. The sizes of these vents are similar. Use tinplate or even plastic plate to make a barrel that is slightly larger than the cross-section of the air outlet, and then cover the barrel on the air outlet when measuring, and then use the anemometer to measure the nozzle of the barrel at multiple points and calculate the average value.

3. Clean air can be obtained through the clean air conditioning circulation fan, high-efficiency air filter, medium-efficiency filter, and primary air filter. The cleanliness is different, and the wind flow direction is different. Of course, it is also necessary to supplement some fresh air through the fresh air outlet, otherwise people will feel stuffy inside.

 Air volume measurement of high-efficiency air outlet: 

1. The detection method of high-efficiency air outlet uses active sampling and passive sampling. Active sampling uses filtering method and impact method. The filtering method allows a certain amount of air to pass through an analytical filter.

2. The impact method can use Anderson sampler, Lute centrifugal sampler, and slit sampler. Passive sampling uses the landing method. The principle of diffusion of open agar plates with suspended particles is used.

3. Of course, with the development of science and technology today, some more sophisticated detection instruments can also be used to quickly detect it.

 Is high efficiency filter leakage rate test: ≤0.01% necessary? 

 What is the acceptance criterion for HEPA filters? 

Most test standards regarding the acceptance criterion for HEPA filter leak rates state that the acceptable leak limit is ultimately determined by the customer and supplier. However, for many applications using HEPA filters or different levels of cleanroom, most adopt a scan test leak criterion of ≤0.01%. Although 0.01% leak rates have been used historically and their origins are related to the accuracy of early photometer test equipment, using a 0.01% leak rate criterion as the acceptance criterion without a scientific and risk-based assessment will lead to problems associated with leak testing and may result in significant operating costs if an over-limit or failure is found in a low-risk area. Filters are not 100% retaining and particles near the MPPS are expected to penetrate the filter partially or entirely. When using lower-level HEPA filters, the factory-performed acceptable leak rate criterion for particles at or near the MPPS may be equal to or greater than the acceptance criterion for field leak rate testing, and testing acceptance criteria becomes more controversial and difficult. This is especially true in areas where leaks may occur. Therefore, when purchasing filters, it is important to consider the filter rating and how it will be tested after installation to avoid unnecessary field test failures.

ISO 14644-3 [33] provides guidance on how to implement alternative leakage criteria. In a risk-based approach, the ideal acceptance criterion is one that reflects the efficiency of the filter used or the cleanliness of the room being tested. ISO 14644-3 uses the factory filter efficiency rating as the basis for negotiating the acceptance criterion. The leakage acceptance criteria for photometric leak testing and particle counter-based leak testing should be the same because the theory and methodology behind both methods are the same. If performed properly, leak tests using a photometer and a particle counter will give the same leak rate results (Meek et al., 2011 [121]).

If the detected leakage exceeds 0.01% of the upstream concentration, it is generally considered that the leakage rate exceeds the maximum permissible standard.

However, for filter systems with an overall efficiency MPPS ≥ 99.95% and less than 99,995% (such as H13 filters), the acceptance standard is 0.1%. If a filter system with an overall efficiency of less than 99.95% MPPS is to be tested, a different acceptance standard is required, depending on the agreement between the customer and the supplier.

 Importance of High Efficiency Particulate Air Filters (HEPA) and Leak Detection Methods and Standards 

Cleanrooms require air filters to prevent contaminants from entering the cleanroom through their HVAC systems. Cleanrooms are controlled environments where the control of temperature/humidity, pressure, and particulate matter is critical for optimal operational performance. Cleanrooms are designed based on the cleanliness required for a specific process. In the semiconductor industry where microchip manufacturing is performed, air filtration has a higher efficiency because microchips are very sensitive to particles, especially small particles that get wedged between the conductive circuits on the wafers when the wafers are handled.

High Efficiency Particulate Air Filters (HEPA), these filters are very effective in contamination control. They filter particles as small as 0.3 microns and are widely used in pharmaceutical facilities. ULPA (Ultra High Particulate Air Filters) filter particles below 0.12 microns and are widely used in semiconductor equipment.

 Importance of Filters in Cleanrooms 

Managing Contamination Control in Cleanrooms through Several Activities High Efficiency Particulate Air Filters or UPLA Filters play a vital role in cleanrooms. High Efficiency Particulate Air (HEPA) filters must be as efficient as 99.97% penetrating particles, 0.3 microns. This efficiency rating is given by the U.S. Department of Energy to qualify as a true HEPA filter.

 HEPA Filter Specifications 

As defined by the U.S. Department of Energy (DOE) standards adopted by most U.S. industries, the minimum resistance or pressure drop a HEPA filter presents to airflow is usually specified at 300 Pascals (0.044 psi) across the filter diameter.

Specifications used by the European Union: European Standard EN 1822-1:2009 defines categories of HEPA filters by their retention at a given most penetrating particle size (MPPS).

According to GMP, filters must be leak-free. This is verified by qualification and periodic leak testing according to ISO 14644-3. Recommended Practices for HEPA Filter Construction, Performance, Labeling, and Certification are maintained by the Institute of Environmental Sciences and Underwriters Laboratories (UL). Key requirements include:

■ IEST-RP-C021 “Testing HEPA and ULPA Media, which governs requirements for filter media

■ IEST-RP-CC001 “High Efficiency Particulate Air Filters and Ultraparticulate Air Filters”, governs overall filter construction and labeling requirements

■ IEST-RP-C034 “HEPA and ULPA Filter Leak Testing, for HEPA and UL PA filter penetration (leakage) testing

■ Testing and certification to UL900 flammability requirements

■ American Standard MIL-STD-282

Other testing standards include:

■ ISO 14644-3 Test Method – Qualified Persons Used During Installed Filter Leakage Testing

■ ISO 29463 (2017) – High Efficiency Filters and Filter Media for Removal of Airborne Particles

■ ISO 16890 (2017) – Air Filters for General Ventilation

■ PIC/s PI 032-2 GMP Guide

■ EN1822 used by HEPA/UPA filter manufacturers

High efficiency filter testing is a key technology and an important step to ensure a safe working environment and improve air quality. Filter test data is more effective in formulating a more scientific maintenance and replacement plan for customers.

 KLC high efficiency filter testing program: 

 1. Smoke test 

During the testing process, we use advanced instruments and technology to accurately measure the filter's capture rate of particles of different sizes and control a variety of environmental variables.

 2. MPPS test 

Comprehensively analyze the filter's performance under high flow conditions to ensure it can effectively maintain good air quality and system efficiency in actual use.

 3. DOP Test 

Used to verify the performance of filters in capturing fine particles of dirt, especially in fields such as pharmaceuticals, electronics and aviation where air quality is extremely high. This test uses DOP aerosol to accurately simulate the filtering effect of fine particles in actual working environments.

From October 23rd to 25th, KLC will appear at BIO EXPO 2024 with innovative filters and clean room equipment, participating in the grand event with biotechnology and clean room elites from around the world. This event not only provided KLC with a platform to showcase its innovative achievements, but also opened a new chapter of in-depth exchanges and cooperation with Turkish and even international counterparts.

This new concept of “Life Sciences 2024 Exhibitions of Turkey” includes 4 industries and 4 special exhibitions in one hand: Analytech 2024, Cleanroom 2024, Pharmanext 2024 and Biotecnica 2024 Exhibitions organized at the same time, in the same venue in order to create “ synergy” and “absolute concentration”.

At the exhibition, KLC's booth attracted the attention of many visitors. We showcased a variety of cutting-edge filters and clean equipment, covering solutions for multiple industries such as medical, pharmaceutical, food and electronics. Our products are known for their efficient filtration performance and excellent clean room control systems, winning high recognition from customers.

This exhibition provides a good platform for KLC to interact with industry partners and potential customers. Our professional team conducted in-depth technical exchanges with participants and shared the latest market trends, product innovations and visions for future development. Attendees showed strong interest in our high-efficiency filtration solutions and provided many case discussions on specific applications.

This exhibition provides KLC with a platform to showcase its strength and seek cooperation opportunities. In the future, we will continue to focus on developing more efficient and energy-saving filters and cleaning equipment to provide customers with first-class solutions. We look forward to working with all industry partners to jointly promote the development of clean technology.

Thank you to all friends who visited the KLC booth at the BIOEXPO exhibition. We look forward to establishing closer contact with you in the days to come and creating a better tomorrow in the clean field!

On April 19, the CPHI Japan 2024 came to a successful conclusion in Tokyo. CPHI JAPAN 2024 hold at Tokyo Big Sight, from April 17th to 19th. KLC showed up with clean room solutions and discussed new development trends and future opportunities in the pharmaceutical industry with experts and audiences.

During the exhibition, KLC displayed a complete set of pharmaceutical clean room equipment and filter products, attracting the attention of many attendees. Participants had an in-depth understanding of product features and application scenarios through communication with KLC representatives.

Going global in 2024 has allowed KLC to increase its visibility and influence in the pharmaceutical industry. KLC promises to continue to be committed to the innovation and development of indoor air solutions, provide customers with better services, and make greater contributions to environmental protection. Looking forward to our next encounter!

In the use of dust-free workshop, in addition to understanding the management system of dust-free workshop, we must also know how to control the humidity of dust-free workshop. The temperature and humidity of dust-free workshop are mainly determined according to process requirements, but under the condition of meeting process requirements, people's comfort should be considered. Therefore, we need to take effective solutions to the situation of high humidity in dust-free workshop.

 How to reduce the high humidity in the dust-free workshop: 

High humidity actually reduces the accumulation of static charge on the surface of the dust-free workshop and clean room. Lower humidity is more suitable for the accumulation of charge and becomes a potentially destructive source of static discharge. When the relative humidity exceeds 50%, the static charge begins to dissipate rapidly, but when the relative humidity is less than 30%, it can persist for a long time on an insulator or ungrounded surface. Therefore, in an environment with high relative humidity, the capillary force of concentrated water forms a connection bond between the particles and the surface, which can increase the adhesion of the particles to the siliceous surface. It is not important when the relative humidity is less than 50%, but when the relative humidity is around 70%, it becomes the main force for adhesion between particles.

 Solutions to high humidity in dust-free workshops: 

1. Increase dehumidification and drying: Add a dehumidifier in the clean workshop to increase the dryness of the workshop, and add it in the air conditioning duct during installation.

2. Seal equipment: Seal the equipment that may be affected as much as possible to reduce the impact of the humid environment in the workshop to achieve the purpose of safe storage.

3. Maintain ventilation: Ventilation can form convection of air inside and outside the workshop. When the temperature difference between inside and outside the workshop is greater, the air will flow faster, and the dehumidification effect on the workshop will naturally be more significant.

4. Moisture absorption in the workshop: In the rainy season or rainy days, when the humidity in the workshop is too high and it is not suitable for product storage, and the humidity outside the workshop is too high, it is not suitable for ventilation and moisture dissipation. You can use moisture absorption in the sealed warehouse to reduce the humidity in the warehouse.

In view of the problem of excessive humidity in the dust-free workshop, the use of a comprehensive solution can effectively improve the control ability of the workshop environment. Strengthening ventilation, using dehumidification equipment, controlling temperature, managing materials and strengthening monitoring are all important measures to ensure the stability of humidity in the dust-free workshop. Through these methods, the smooth progress of the production process can be ensured and the quality and safety of the products can be maintained.