COATING SYSTEMS FOR CLEANROOMS AND CLEAN MANUFACTURING

| Cleanrooms and clean manufacturing areas |

Coating systems for cleanrooms and clean manufacturing areas Floor-wall-ceiling

It should be noted that the details, illustrations, general technical information, and drawings contained in this brochure are only general proposals and details which merely describe the basic functions schematically. They are not dimensionally accurate. The applicator/customer is independently responsible for determining the suitability and completeness for the product in question. Neighbouring works are described only schematically. All specifications and information must be adjusted or agreed in the light of local conditions and do not constitute work, detail or installation plans. The technical specifications and product information in the Technical Data Sheets and in system descriptions/certificates must be observed.

2 | Cleanrooms and clean manufacturing areas

Contents

It has to be clean! Cleanrooms and clean manufacturing areas

4

Standards and regulations Classifications bring safety

6

Epoxy resins for ceilings, walls and floors Smooth surfaces and low particle formation

10

Cleanroom coating systems for floors Overview of the floor systems

12

Cleanroom coating systems for walls and ceilings Overview of the wall and ceiling systems

14

Contents | 3

It has to be clean! Cleanrooms and clean manufacturing areas

Manufacturing under cleanroom or clean conditions is essential for a growing number of companies, in order that they can safeguard their process operations and the quality of their components. The requirements of the various industrial sectors differ significantly. Cleanrooms and clean manufacturing areas are used primarily in the following industrial sectors: Clean rooms • Semiconductor industry • Photovoltaics • Microsystem technology • Food industry • Pharmaceutical industry • Biotechnology • Aviation and space industry

4 | Introduction

Clean manufacturing areas • Automobile and supplier industries • Machine engineering Equipment, which also includes the floor, wall and ceiling coatings, has a significant influence on the room air quality. The different requirements and the necessary properties of the coating systems for these are described below. Cleanliness areas Cleanliness areas are set up to protect sensitive surfaces and items. The purpose of a cleanliness area is to maintain as far as possible the specified cleanliness quality of components, ancillary materials and assem-

blies during processing. The cleanliness level should not be reduced by the influence of environmental factors. Bringing contamination into a cleanliness area must be avoided. Any contamination, which is incurred there, is to be kept in check and then eliminated. The design, required measures and method of use for cleanliness areas are based on cleanliness requirements, which are related to the particular product. The critical particle sizes are generally between 5 μm and 1,000 μm.

The classification of the cleanliness levels in accordance with VDA 19 Part 2 is in 4 levels: • Cleanliness level 0 (SaS0): Non-controlled area • Cleanliness level 1 (SaS1): Clean zone • Cleanliness level 2 (SaS2): Clean manufacturing area • Cleanliness level 3 (SaS3): Cleanroom In order to fulfil the requirements from Cleanliness level 1 onwards, floors must have primarily good abrasion resistance (low particle formation on the surface when it is being used), and good mechanical resistance. A smooth surface, which is easy to clean, is also necessary. Depending on the manufacturing process, other properties such as for example chemical resistance, slip resistance, electrical dissipation capability and crack bridging may be added. Coating systems, which are made of epoxy resin or polyurethane and which are also employed in other areas of industry, are normally used up to Cleanliness level 2.

Clean rooms A cleanroom is defined as follows in accordance with DIN EN ISO 14644-1 and VDI 2083 Page 1: “A room, in which the concentration of airborne particles is controlled, and which is designed and used in such a way, that the number of particles, which have been brought into the room or which have arisen and been deposited in the room, is as small as possible, and where other parameters relevant to cleanliness, such as temperature, humidity and pressure are controlled as required.” In contrast to the particle sizes in cleanliness areas, particle sizes of 0.1 μm to 5 μm are relevant here. In order to keep the share of more or less severely contaminated outside air as small as possible, normally rooms or storeys outside the actual cleanroom are used for air circulation. This means that it is also necessary there, that floors, walls and ceilings, which mostly consist of reinforced concrete, have a cleanroom-compatible surface. These measures have a significant influence on the lifespan of the filter elements for the cleanroom.

In addition to the quality of the supply air and method of introducing it as well as to the surfaces and personnel, the other critical influencing factor in the cleanliness of a cleanroom is the equipment in the room. The equipment includes internal fixtures and fittings such as walls, doors, ceilings and floors. Significant factors in the cleanroom compatibility of equipment are: • Emission of airborne particles • Outgassing behaviour • Electrostatic discharge properties • Cleanability • Resistance to chemicals and disinfectants • Smooth and crack-free surface • Metabolising potential and microbicidity

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Air Return Return air Shaft shaft

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Simplified schematic illustration for semi conductor manufacturing

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Introduction | 5

Standards and regulations Classifications bring safety

The requirements of different industrial sectors vary considerably. While a low level of outgassing from equipment is mandatory for the manufacture of semiconductors, this has mostly played no role as yet in the manufacture of pharmaceutical products. There are similarly differences in the particle cleanliness classes between DIN EN ISO 14644-1 and GMP (Good Manufacturing Practice) or cGMP, which applies to the manufacture of human and veterinary medical products. The particle cleanliness classes for air in accordance with DIN EN 14644-1 are divided into Classes 1 to 9, whereby the highest permitted particle count is the lowest in Class 1. In GMP the division is made into Classes A to D, whereby Class A corresponds approximately to ISO Class 5. Airborne particles represent the largest problem for most production processes. AMC (= Airborne Molecular Contamination) is also playing an ever greater role. These are molecular (chemical, non-particulate) substances in a gas or vapour phase within the atmosphere of a cleanroom area, which could have a harmful effect on the product, process, equipment or personnel. Outgassing from equipment materials, such as for example wall/ceiling/floor coatings, can have negative effects to a significant degree. Examples of this are corrosion effects on metallic conductor strips, defects in lithographic processes, shortened service intervals and life cycles of optics, and the alteration of electrical properties of wafers due to undesirable effects.

6 | Standards and regulations

Classification of air purity on the basis of chemical concentration (ACC) ISO ACC class

Concentration g/m3

Concentration μg/m3

Concentration ng/m3

0

100

10-6 (1 000 000)

109 (1 000 000 000)

-1

10-1

10-5 (100 000)

108 (100 000 000)

-2

10-2

10-4 (10 000)

107 (10 000 000)

-3

10-3

10-3 (1 000)

106 (1 000 000)

-4

10-4

10-2 (100)

105 (100 000)

-5

10-5

10-1 (10)

104 (10 000)

-6

10-6

10-0 (1)

103 (1 000)

-7

10-7

10-1 (0.1)

102 (100)

-8

10-8

10-2 (0.01)

101 (10)

-9

10-9

10-3 (0.001)

100 (1)

-10

10-10

10-4 (0.000 1)

10-1 (0.1)

-11

10-11

10-5 (0.000 01)

10-2 (0.01)

-12

10-12

10-6 (0.000 001)

10-3 (0.001)

Source: DIN EN ISO 14644-8:2013-06

Classification of the various air particle cleanliness classes Nomenclature

DIN EN ISO 14644-1a)

EU GMP Guidelinea)

Maximum permitted particle count per cubic metre of air in accordance with DIN EN ISO 14644-1 US Fed. Std. 209Ea)

≥ 0.1 µm

≥ 0.2 µm

1

10

2

2

100

3 M 1.5 (1)a) 4 M 2.5 (10)b) 5

≥ 0.3 µm

≥ 0.5 µm

24

10

4

1 000

237

102

35

1 240

265

106

35

10 000

2 370

1 020

352

12 400

2 650

1 060

353

1 000 000

23 700

10 200

3 520

A/B

≥ 5.0 µm

8

83

832

29

8 320

293

3 500 M 3.5 (100)

b)

6 M 4.5 (1 000)

b)

7

26 500

10 600

3 530

237 000

102 000

35 200 35 300 352 000

C M 5.5 (10 000)b) 8 D M 6.5 (100 000)b) 9

247 83 200

2 930

350 000

2 000

353 000

2 470

3 520 000

Source: VDI 2083, page 1

≥ 1.0 µm

832 000

29 300

3 500 000

20 000

3 530 000

24 700

35 200 000

8 320 000

239 000

a) Observe different operating statuses (depicted: Empty running) b) Division into classes in cubic feet

Standards and regulations | 7

Standards and regulations

No testing criteria for equipment, which also includes coating systems for floors, walls and ceilings, have been specified up to now in any standards or guidelines for cleanrooms. There has been only indirect information on the composition of room air to be produced or maintained in cleanrooms. Cleanroom manufacturers and operators have therefore specified the criteria for systems in cleanrooms on the basis of experience. Their own testing procedures have in part been developed, such as for example through the M+W Group with its “Specifications for semiconductor cleanrooms”. An industry alliance, “Cleanroom Suitable Materials (CSM)”, arose from an initiative by the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) in Stuttgart, in order to work out testing methods for the cleanroom compatibility of equipment and to develop products, which are optimised for these tasks. Thanks to the knowledge gained by the CSM Industry Association, test criteria for the cleanroom/cleanliness compatibility of materials were described for the first time in the VDI Directive 2083, Page 17 (June 2013).

8 | Standards and regulations

Depending on the area of application, the following requirements are placed on coating systems: • Good abrasion resistance (low particle formation) • Good mechanical resistance • Good chemical resistance • Low outgassing • Smooth, easily cleanable surface • Resistant to disinfectants • Biostatic or microbicidal • Dissipative • Crack-bridging The cleanroom compatibility of coating systems has since been able to be proved by means of testing procedures. This means significantly greater safety for the construction and operation of a cleanroom.

Supplementary requirements in biotechnology In laboratories for research, development and microbiological analysis, in which there is contact with microorganisms as part of bacteriology, mycology, virology and parasitology, and/or in which genetic work is being carried out, the main focus is on ensuring, that no microorganisms, which are dangerous to humans, animals, plants or the environment, can escape from the laboratory. These laboratories are classified into four safety levels, S 1 to S 4, in accordance with DIN EN 12128, whereby S 1 is the lowest safety level and S 4 the highest. As regards safety levels from S 3 onwards, the surfaces of work tables, floors, walls and ceilings must be easy to clean and easily accessible for upkeep. The surfaces must be impermeable to water and resistant to disinfectants, cleaning agents, acids, solutions, solvents and other chemicals, which are normally used. Most coating systems have since had to be crack-bridging, so that no microorganisms, which could otherwise remain untouched by wiping disinfection, can become established in any cracks, which may subsequently arise in the building.

Cleanroom Suitable Materials An industry alliance, “Cleanroom Suitable Materials (CSM)”, was created on the initiative of the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) in Stuttgart. Testing methods have been developed here to test materials for their cleanroom compatibility. StoCretec GmbH actively collaborates as an “Industrial Alliance Member” in the further development of suitable materials for the coating of walls/ ceilings/floors. The products have been tested by the IPA in accordance with the CSM test parameters. Further information at www.cleanroomnet.de.

Standards and regulations | 9

Epoxy resins for ceilings, walls and floors Smooth surfaces and low particle formation

Ground

Coating systems based on epoxy resin are ideally suited to the requirements of cleanrooms. They have proven themselves primarily due to their smooth surface and very good chemical resistance. They also have very good abrasion performance and therefore very low particle formation, when subjected to mechanical stress such as for example contact with persons or vehicles. The outgassing behaviour has also been further improved in recent years due to targeted selection of material ingredients as part of the development of the products. The latest generation of epoxy resin dispersions or emulsions contain only water and hardly any share of volatile components. Coating systems generally consist of the following work stages: • Substrate preparation • Primer • Levelling layer • Finishing coat

4

3

1 2 3 4

Substrate Primer Levelling layer Finishing coat

2 1

Wall

1 Substrate 2 Primer 3 Filling 4 Sealing 4

3

2

1

Substrate preparation by shot-blasting

10 | System structure

Substrate preparation by grinding

Substrate preparation by high-pressure water jetting

Holes and shrinkage holes in the prepared concrete surface

Closing of holes and shrinkage holes with levelling filler coating

Coatings on floors, walls and ceilings

As regards horizontal surfaces subject to vehicle traffic, low-dust shot-blasting has become established in recent years as the most economic procedure for substrate preparation. Grinding with a diamond plate grinder is used on small surfaces and in areas, which are difficult to access. High-pressure water jetting is normally used on large surfaces for walls and ceilings, primarily in new buildings. The primer is an important component part of a coating system, since it ensures that there is a permanent bond between the following coating and the substrate. In the case of reinforced concrete surfaces, there are open pores and shrinkage holes present after the substrate preparation, and these have to be closed by means of a levelling layer, so that they are not transferred to the finishing coat.

A self-spreading epoxy resin coating, which is filled with quartz sand, of 1-2 mm layer thickness is generally used as the finishing coat on horizontal surfaces. In the case of wall and ceiling surface areas, which are not exposed to any mechanical stress such as contact with persons or vehicles, sealing with epoxy resin to a layer thickness of 0.1-0.2 mm is generally sufficient. A glass fleece can be worked into the coating system in order to achieve crack bridging. It is strongly recommended, that test surfaces are created in advance of the work, so that a picture of the edge zone of the concrete is formed. Depending on the concrete quality and the quality level of the installation, this can be very variable as regards suction behaviour, surface tensile strength, roughness and frequency of pores and shrinkage holes.

Coated wafer table in semi conductor manufacturing

Coating with a terrazzo look in a pharmaceutical company

System structure | 11

Cleanroom coating systems for floors Overview of the floor systems Cleanroom coating systems for floors Cleanroom Floor System 1

Cleanroom Floor System 2



0.4 mm

0.4 mm



Substrate Dry concrete Dry cement screed Concrete with increased moisture Cement screed with increased moisture Magnesia screed Calcium sulphate screed

Properties Rigid Crack-bridging Suitable for vehicle traffic with Vulkollan and polyamide wheels System layer thickness

1.5-2 mm

1.5-2 mm

> 2 mm

> 2 mm

1.5-2 mm

> 2.5 mm

Prime coating

StoPox GH 205 Scattering with quartz sand 0.3-0.8 mm

StoPox GH 205 Scattering with quartz sand 0.3-0.8 mm

StoPox WHG Grund 100 and scattering with quartz sand 0.3-0.8 mm

StoPox WHG Grund 100 and scattering with quartz sand 0.3-0.8 mm

StoPox WG 100

StoPox GH 205, scattering with quartz sand 0.3-0.8 mm

Scratch coat

StoPox GH 205 and quartz sand

StoPox GH 205 and quartz sand

StoPox WHG Grund 100 and quartz sand

StoPox WHG Grund 100 and quartz sand

StoPox WG 100

StoPox BB OS

StoPox WL 110

StoPox WHG Leit 110

StoPox KU 611

StoPox WHG Deck 110

StoPox WHG Deck 100

StoPox WB 100

StoPox BB T 200

StoPox WL 100

StoPox WL 150

Smooth, gloss surface Silk matt, pore-free surface with a terrazzo look Electrically conductive Water vapour permeable

System structure

Conductive intermediate Coating Sealing

StoPox BB OS

System view

12 | Floor systems

The detailed technical specifications and information on the products contained in the Technical Data Sheets and approvals must be observed.

Cleanroom coating systems for floors Cleanroom Floor System 1






Test certificates Decontaminability »excellent« Outgassing behaviour Particle formation Resistance to disinfectants Resistance to fungi and bacteria Suitability for indirect contact with food Approval § 62 WHG


Floor systems | 13

Cleanroom coating systems for walls and ceilings Overview of the wall and ceiling systems

Cleanroom coating systems for walls and ceilings Cleanroom Wall/ Ceiling System 1

Cleanroom Wall/ Ceiling System 2




0.4 mm

0.4 mm 1.5-2 mm

Substrate Dry concrete Concrete with increased moisture Render of mortar group 2 Render of mortar group 3 Gypsum plasterboard

Properties Rigid Crack-bridging System layer thickness

1.5-2 mm

1.5-2 mm

1.5-2 mm

1.5-2 mm

Prime coating

Concrete: StoPox WG 100

Concrete: StoPrim Plex Render: StoPrep In



Level filling

StoPox WS 50

StoLevell In Z

StoLevell In Z

StoLevell In Z

Stipple filling

StoPox WB 50

StoLevell In XXL

StoLevell In Z

StoLevell In Z

All-over filling

StoPox WB 50

StoLevell In XXL

StoLevell In Z

StoLevell In Z

Smooth, gloss surface Water vapour permeable

System structure

Gypsum plasterboards: StoLevell In Fill

Grinding Prime coating

StoPrim Plex

StoPrim Plex

Glass fleece

StoTap Pro 100 P With StoTex Coll adhesive

StoTap Pro 100 P With StoTex Coll adhesive

Prime coating

StoPox WL 100

StoPox WL 100

StoPox WL 100 in 2 layers


Sealing




System view

14 | Wall and ceiling systems


Cleanroom coating systems for walls and ceilings Cleanroom Wall/ Ceiling System 1





Test certificates Decontaminability »very good« Outgassing behaviour Particle formation Resistance to disinfectants Resistance to fungi and bacteria Suitability for indirect contact with food

Wall and ceiling systems | 15

COATING SYSTEMS FOR CLEANROOMS AND CLEAN MANUFACTURING

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