Clean room application

1.Clean Room / Aseptic Clean Room

Clean Room is a room in which the concentration of airborne particles is controlled, and which is constructed and used in a manner to minimize the introduction, generation, and retention of particles inside the room, and in which other relevant parameters, e.g. temperature, humidity, and pressure, are controlled as necessary. Also, the illumination, hazardous steam, and airflow direction and its velocity are also defined.
Aseptic Clean Room is a room where the Microorganisms such as bacteria or virus and biological particles are more strictly controlled.

Industrial Clean Room ICR

It is the Clean Room for industrial use, such as Precision industries, electric industries, etc.

Biological Clean Room BCR

It is the aseptic Clean Room for biological medicine or laboratories. Most of the bacteria or virus are attached to the airborne particles, which can be filtered with Filter System. However, finer bacteria can be sterilized by ultra-violet ray lamp or Hydrogen Peroxide Gas.

2.Features for Clean Room Air-conditioning

I.Temperature and humidity requirements are higher than general air-con.

The temperature requirement for general air-con is between 18°C and 26°C and the relative humidity is between 40% and 65%; while the temperature in Clean Room should be controlled between 22°C and 24°C and the humidity in it should be between 45% and 55%.

II.Constant temperature and humidity control

It is extremely temperature-sensitive for the semiconductor industry; therefore, the temperature and humidity should be controlled within ± 1°C and ± 3% in most of the Clean Room areas.

III.More air needed to balance the air pressure in Clean Room

A large amount of the chemicals and toxic gas will be required during the semiconductor production. Therefore, there will also be a huge amount of gas exhausted due to the volatile gas and exhaust gas. To maintain positive pressure inside the Clean Room, the air supply into the Clean Room is also relatively increased.

IV.Twenty-Four Seven running and monitoring on Air-con system

Part of the machines in the semiconductor production are highly sensitive to the temperature/humidity variation, such as the Stepper in Photo lithography area. A slight change of the temperature or humidity would affect the accuracy of the device. Moreover, the products like chips should be put in the environment with constant temperature and humidity. Therefore, the air-con system should be strictly monitored and managed.

V.Air pressure inside the Clean Room in the semiconductor factories

For the semiconductor factories, the air pressure in the Clean Room should be higher than the outside. Besides avoiding the influence from the temperature, humidity, and particles outside the Clean Room, it also helps extend the lifetime of the ULPA filter. However, the pressure difference should be constrained to avoid the cost increase from the increased out bounding air from Clean Room.

VI.Airflow direction

In order to remove the airborne particles inside the Clean Room, the air velocity shall reach the certain standard. Also, the airflow direction shall be controlled based on various levels of the Clean Room.

3.Clean Room System

The Clean Room system would produce clean air that is conformed to the specification. The clean air shall be steadily and continuously supplied to the FAB. Generally speaking, the source for producing clean air is called OUTSIDE AIR. It will undergo various of processing units in the Clean Room to produce the clean air that conforms to the specification. The following is the simplified process: The Outside air goes into the Make-up Air Unit (or MAU) to pre-filter the particle and control the temperature/humidity. After that, the air goes to the Mech. Chase. Inside the Chase, the circular air in the Clean Room and the supplying air from the MAU are mixed, and Dry Cooling Coil will cool down the air inside the Mech. Chase to the requested temperature by the Clean Room specification. Then the Fan Filter Unit (or FFU) enables the airflow cycle in the Clean Room to remove the particles and heat. Last, the air will be supplied to FAB area after filtered by the Ultra-low penetration air (or ULPA Filter).

4.Definition of Cleanliness

It means the capability for the Clean Room to effectively control the particle number in the specific room. To define the function of different types of the Clean Room, we define it based on the particles of “Specific Size” in “Specific Volume”.
Take the particle diameter above 0.5μm for example:

Countryside 10,000,000 – 50,000,000 particles/m3
City 100,000,000 – 500,000,000 particles/m3
Indoors 100,000,000 – 1,000,000,000 particles/m3
ISO Class 5 control within 3,520 particles/m3
FS 209E Class 100 control within 3,520 particles/m3

5.Clean Room Classifications

IndustryCleanliness
ISO 2ISO 3ISO 4ISO 5ISO 6ISO 7ISO 8
- 209E Class
1
209E Class
10
209E Class
100
209E Class
1,000
209E Class
10,000
209E Class
1000,00
ICRSemiconductor chip manufacturer      
Semiconductor component supplier Front end    
Back end          
LCD Manufacturer        
Hard Disk manufacturer        
Precision industry manufacturer      
Mask manufacturer        
PCB manufacturer      
BCRPharmaceutical manufacturer Filling area          
Packing area        
Hospital Aseptic therapy room        
Aseptic operation room          
Food processing manufacturer UHT milk          
Fresh vegetables, fruits, boxed meal, bread          
Animal laboratory Aseptic animal laboratory          
SPF animal        

Worldwide standard

Cleanliness

The cleanroom classification standards FS 209E and ISO 14644-1 require specific particle count measurements and calculations to classify the cleanliness level of a cleanroom or clean area.

ISO 14644-1

Maximum concentration limits (particles/m3 )
Classification Number (N)0.1μm0.2μm0.3μm0.5μm1.0μm5.0μm
ISO Class 1 10 2 - - - -
ISO Class 2 100 24 10 4 - -
ISO Class 3 1,000 237 102 35.2 8 -
ISO Class 4 10,000 2,370 1,020 352 83 -
ISO Class 5 100,000 23,700 10,200 3,520 832 29
ISO Class 6 1,000,000 237,000 102,000 35,200 83,200 293
ISO Class 7 - - - 352,000 832,000 2,930
ISO Class 8 - - - 35,200,000 8,320,000 29,300
ISO Class 9 - - - - - 293,000

Federal Standard 209E Airborne Particulate Cleanliness Classes

CR CleanlinessDiameter for Airborne Particle
0.1μm0.2μm0.3μm0.5μm0.5μm
Volume UnitsVolume UnitsVolume UnitsVolume UnitsVolume Units
SIClass (m3) (ft3) (m3) (ft3) (m3) (ft3) (m3) (ft3) (m3) (ft3)
M1  350 9.91 75.7 2.14 30.9 0.875 10.0 0.283 - -
M1.51 1240 35.0 265 7.50 106 3.00 35.3 1.00 - -
M2  3,500 99.1 757 21.4 309 8.75 100 2.83 - -
M2.510 12,400 350 2,650 75.0 1,060 30.0 353 10.0 - -
M3  35,000 991 7,570 214 3,090 87.5 1,000 28.3 - -
M3.5100 - - 26,500 750 10.600 300 3,530 100 - -
M4  - - 75,700 2,140 30,900 875 10,000 283 - -
M4.51000 - - - - - - 35,300 1,000 247 7.00
M5  - - - - - - 100,000 2,830 618 17.5
M5.510,000 - - - - - - 353,000 10,000 2,470 70.0
M6  - - - - - - 1,000,000 28,300 6,180 175
M6.5100,000 - - - - - - 3,530,000 100,00 24,700 700
M7  - - - - - - 10,000,000 283,000 61,800 1,750

JIS B 9920

ClassMaximum concentration limits (particles/m3 )
0.1μm0.2μm0.3μm0.5μm1μm05μm
Class1 10 2 - - - -
Class2 100 24 10 4 - -
Class3 100 237 102 35 8 -
Class4 10,000 2,370 1,020 352 83 -
Class5 100,000 23,700 10,200 3,520 832 29
Class6 - 237,000 102,000 35,200 8,320 293
Class7 - - - 352,000 83,200 2,930
Class8 - - - 3,520,000 832,000 29,300
Class9 - - - 35,200,000 8,320,000 293,000

Britain BS 5295

ClasssMaximum concentration limits (particles/m3 )
0.5μm1.0μm5.0μm10μm25μm
Class 1 3,000 - 0 0 0
Class 2 300,000 - 2,000 30 -
Class 3 - 1,000,000 20,000 4,000 300
Class 4 - - 200,000 40,000 4,000

Worldwide Standard comparison

Worldwide StandardClass
ISO 14644-1ISO 3ISO 4ISO 5ISO 6ISO 7ISO 8
FS 209E Class 1 Class 10 Class 100 Class 1000 Class 10000 Class 100000
FS 209E(SI) M1.5 M2.5 M3.5 M4.5 M5.5 M6.5
JIS B 9920 Class 3 Class 4 Class 5 Class 6 Class 7 Class 8
Britain BS 5295 C D E/F G/H J K
Germany VD I.2083 1C 2 3 4 5 6
Australia AS 1386 0.035 0.35 3.5 35 350 3500
France AFNOR X44101 - - 4,000 - 4,000 4,000,000
Grade - A/B - C

PIC/S GMP Guide

For the manufacture of sterile medicinal products

The “in operation” and “at rest” states should be defined for each clean room or suite of clean rooms. For the manufacture of sterile medicinal products 4 grades can be distinguished:

Description
Grade A The local zone for high risk operations, e.g. filling zone, stopper bowls, open ampoules and vials, making aseptic connections. Normally such conditions are provided by a laminar air flow work station. Laminar air flow systems should provide a homogeneous air speed in a range of 0.36 – 0.54 m/s (guidance value) at the working position in open clean room applications. The maintenance of laminarity should be demonstrated and validated. A uni-directional air flow and lower velocities may be used in closed isolators and glove boxes.
Grade B For aseptic preparation and filling, this is the background environment for the grade A zone.
Grade C Clean areas for carrying out less critical stages in the manufacture of sterile products

Clean rooms and clean air devices should be classified in accordance with EN ISO 14644-1. Classification should be clearly differentiated from operational process environmental monitoring. The maximum permitted airborne particle concentration for each grade is given in the following table:

Maximum permitted number of particles/m3 equal to or greater than the tabulated size
 At restIn operation
Grade0.5μm5μm0.5μm5μm
A 3,500 0 3,500 0
B 3,500 0 3,500 2,000
C 350,000 2,000 350,000 20,000
D 3,500,000 20,000 not defined not defined
  • For classification purposes in Grade A zones, a minimum sample volume of 1m³ should be taken per sample location.
  • For Grade A the airborne particle classification is ISO 4.8 dictated by the limit for particles ≥5.0 μm.
  • For Grade B (at rest) the airborne particle classification is ISO 5 for both considered particle sizes.
  • For Grade C (at rest & in operation) the airborne particle classification is ISO 7 and ISO 8 respectively.
  • For Grade D (at rest) the airborne particle classification is ISO 8.
  • For classification purposes EN/ISO 14644-1 methodology defines both the minimum number of sample locations and the sample size based on the class limit of the largest considered particle size and the method of evaluation of the data collected.

Examples of operations to be carried out in the various grades are given in the table below :

GradeExamples of operations for terminally sterilised products
A Filling of products, when unusually at risk
B Preparation of solutions, when unusually at risk. Filling of products
D Preparation of solutions and components for subsequent filling
GradeExamples of operations for aseptic preparations
A Aseptic preparation and filling
B Preparation of solutions to be filtered
D Handling of components after washing

HEPA Information

EN 1822:2009

Filter ClassOverall ValueLocal Value
Efficiency(%) Penetration(%) Efficiency(%) Penetration(%)
E10 ≧85 ≦15 - -
E11 ≧95 ≦5 - -
E12 ≧99.5 ≦0.5 - -
H13 ≧99.95 ≦0.05 ≧99.75 ≦0.25
H14 ≧99.995 ≦0.005 ≧99.975 ≦0.025
U15 ≧99.9995 ≦0.0005 ≧99.9975 ≦0.0025
U16 ≧99.99995 ≦0.00005 ≧99.99975 ≦0.00025
U17 ≧99.999995 ≦0.000005 ≧99.9999 ≦0.001
  • EPA 10 - EPA 12: Efficiency Particulate Air Filters
  • HEPA 13 - HEPA 14: High Efficiency Particulate Air Filters
  • ULPA 15 - ULPA 17: Ultra Low Penetration Air Filters

DIN EN 779:2012

GroupClassFinal pressure
drop (Pa)
Average
arrestance (%)
Average
efficiency (%)
Minimum efficiency
@0.4µm (%)
Coarse dust filterG1 250 50 ≤Am< 65 - -
G2 250 65 ≤ Am< 80 - -
G3 250 80 ≤ Am< 90 - -
G4 250 90 ≤ Am - -
MediumM5 450 - 40 ≤ Em< 60 -
M6 450 - 60 ≤ Em< 80 -
Fine dust
filter
F7 450 - 80 ≤ Em< 90 35
F8 450 - 90 ≤ Em< 95 55
F9 450 - 95 ≤ Em 70

ISO 29463:2011

Filter ClassOverall ValueLocal Value
Efficiency(%) Penetration(%) Efficiency(%) Penetration(%)
ISO 15 E ≧95 ≦5 - --
ISO 20 E ≧99 ≦1 - --
ISO 25 E ≧99.5 ≦0.5 - --
ISO 30 E ≧99.90 ≦0.1 - --
ISO 35 H ≧99.95 ≦0.05 ≧99.75 ≦0.25
ISO 40 Hd ≧99.99 ≦0.01 ≧99.95 ≦0.05
ISO 45 Hd ≧99.995 ≦0.005 ≧99.975 ≦0.025
ISO 50 U ≧99.999 ≦0.001 ≧99.995 ≦0.005
ISO 55 U ≧99.999 5 ≦0.000 5 ≧99.997 5 ≦0.002 5
ISO 60 U ≧99.999 9 ≦0.000 1 ≧99.999 5 ≦0.000 5
ISO 65 U ≧99.999 95 ≦0.000 05 ≧99.999 75 ≦0.000 25
ISO 70 U ≧99.999 99 ≦0.000 01 ≧99.999 9 ≦0.000 1
ISO 75 U ≧99.999 995 ≦0.000 005 ≧99.999 9 ≦0.000 1

Please note: These charts provide approximate data regarding various filter classes for reference purposes only. Specific data applicable to an intended application must be determined at the expected face velocity.

Filter Integrity Test

PAO Method

(For testing HEPA) In the PAO test, a gas type of smoke will be generated by the PAO generator. After using the photometer to test the concentration on the upstream of the HEPA, a particle counter will be put at the air exhaust area to test the PAO concentration that passes through HEPA. The distance between the particle counter and HEPA will be around 25mm with testing speed at 50mm/sec. The test range includes HEPA filter and its connecting area. However, there are no related guidelines on the measurement method. Just make sure the whole HEPA covered area are tested for leakage. If there are particles over 0.03 are tested, hold the particle counter for 10 sec and then test.

back and forth at the range of 100mm. Once the particles are less than 0.03, proceed the test.

PAO efficiency (%) = ( 1-particle concentration at the HEPA air exhaust area / particle concentration at the HEPA upstream area ) × 100%.

Colorimetry

(For testing Medium Filter or Bag Filter) This is to test the integrity of the Medium Filter mainly for particle size ≧1μm. There will be the same filter indicator paper at the up/downstream of the filter. After sampling, we calculate the filter integrity based on its transparency variation. Normally the NBS method and ASHRAE method ( 52.1 —92 Standard ) are applied. In 1968年, after modification and consolidation, it is called ASHRAE Efficiency or NBS. Both represent Colorimetry.

Q1:The sampling air volume through the upstream indicator paper.
Q2:The sampling air volume through the downstream indicator paper.
O1:The opacity of the upstream indicator paper with particles on it.
O2:The opacity of the downstream indicator paper with particles on it.
Colorimetry efficiency (%)=( 1- Q1/Q2×Q2/Q1)×100%

Arrestance

(For testing pre-filter) This is to test the efficiency of the pre-filter on larger particles which sizes are ≧5μm.
Normally AFI method (in 1960) and ASHRAE method (52.1—92 Standard) are applied.
It is called ASHRAE Arrestance or AFI. Both represent Arrestance.

Wf:The particle quantity supplied at the upstream of the filter(g)
Wp:The weight of the particles attached on the filter(g)
Arrestance efficiency (%)=( 1- Wp/Wf)×100%

When to conduct Leak test?
  • HEPA replacement
  • Machine re-installation
  • Regular test (at least once a year)

After-sales service

Professional Technique AIRTECH customer service engineers are all authorized by AIRTECH Japan.
We conform to the International Inspection Procedures to make sure we
offer the best technique and support.
Strick control   All the test equipment is under regular maintenance and calibration to
make sure our quality conforms with International standard.
Main Products
  • Air shower
  • Air curtain
  • Clean Booth
  • Clean Bench
  • Biological Safety Cabinet
  • Fan Filter Unit
  • Fume Hood
  • H2O2 sterilization
  • Sterility Testing Isolator
  • Pass Box
  • RABS
  • TCC
Test Items
  • HEPA FILTER Leakage Check
  • Air Velocity and Volume Check
  • Cleanliness Check
  • Vibration Check
  • Illuminance Check
  • Noise Check
  • Airflow Check
  • Differential Pressure gauge Check
  • Power Consumption Check
  • Insulation Resistance Check
  • Operation Check
Immediate support  We have enough stock to make sure we can deliver the spare parts within
the short period of time.
Warranty 1.One year after we ship out.
2.If below conditions occur, there will be certain cost.
  • Mal-usage or re-assembly by personnel.
  • Re-installation or damage due to falling or crashing
  • Natural calamities, damage caused by mal-usage on power/voltage
  • Consumables (e.g. Filters) replacement, etc.

Remark 1: Testing items will vary from product type.
Remark 2: The warranty items are only applied in Taiwan.

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